What is an Operating System?

An operating system is a program designed to run other programs on a computer. A computer’s operating system is its most important program. It is considered the backbone of a computer, managing both software and hardware resources. Operating systems are responsible for everything from the control and allocation of memory to recognizing input from external devices and transmitting output to computer displays. They also manage files on computer hard drives and control peripherals, like printers and scanners.

The operating system of a large computer system has even more work to do. Such operating systems monitor different programs and users, making sure everything runs smoothly, without interference, despite the fact that numerous devices and programs are used simultaneously. An operating system also has a vital role to play in security. Its job includes preventing unauthorized users from accessing the computer system.

There are multiuser, multiprocessing, multitasking, multithreading, and real-time operating systems. A multiuser operating system enables multiple users to run programs simultaneously. This type of operating system may be used for just a few people or hundreds of them. In fact, there are some operating systems that are used to allow thousands of people to run programs at the same time.

A multiprocessing operating system allows a program to run on more than one central processing unit (CPU) at a time. This can come in very handy in some work environments, at schools, and even for some home-computing situations. Multitasking operating systems work a little differently; they make it possible to run more than one program at a time. Multithreading operating systems are even more different, allowing varied parts of one program to be used simultaneously.

Real-time operating systems are designed to allow computers to process and respond to input instantly. Usually, general-purpose operating systems, such as disk operating system (DOS), are not considered real time, as they may require seconds or minutes to respond to input. Real-time operating systems are typically used when computers must react to the consistent input of information without delay. For example, real-time operating systems may be used in navigation.

Today’s operating systems tend to have graphical user interfaces (GUIs) that employ pointing devices for input. A mouse is an example of such a pointing device, as is a stylus. Commonly used operating systems for IBM-compatible personal computers include Microsoft Windows, Linux, and Unix variations. For Macintosh computers, Mac OS X, Linux, BSD, and some Windows variants are commonly used.

What are the Advantages of Hiring a Computer Administrator?

Most companies, large or small, have a computer network of some description. As everyone knows, networks and computers crash and only someone with the right knowledge can bring them back online. A computer administrator usually has this job.

The computer administrator may have other techs working under him or her, but the primary responsibility for the network rests on his or her shoulders. A computer administrator working in a large corporation may have a whole network of techs to rely on. A computer administrator at a small company may only have one or two techs, if any, working with him.

The computer administrator may find herself installing software one day, doing server maintenance the next and tutoring an employee on the system the next day. A computer administrator usually wears several "hats" in a smaller company. In general, a computer administrator will have a degree in computer science or programming, and will be familiar with the most common operating systems used in the corporate world.

A computer administrator often begins a career at the bottom of the ladder, as a tech, doing the workaday tasks found with all computer systems. As he or she learns more about dealing with computers and technology, promotion usually follows. No degree is a substitute for the experience that a computer administrator gains on the job.

When a company hires a computer administrator, it is making a wise investment in resources. Someone who has just an offhand knowledge of computers will eventually run into a problem he cannot handle, nor will he be capable of setting up a complex network. A computer administrator can handle these duties, and more.

When a company hires a good computer administrator, it is making certain someone is on the payroll who can protect its technology and maintain the function of the computer network. Few things are more important in an age where the most sensitive of company information is stored in a computer network.

How Do I Improve my Network Security?

Network security measures are vital to prevent unauthorized users accessing files on your computer. Such measures are particularly important now that many people have "always-on" broadband connections. As well as preventing data loss and security breaches, such measures can stop your computer being used as part of a cyberattack.

An effective firewall is arguably the most important network security measure. It acts a complete block between your computer or network and the outside world, such that only data from specifically authorized websites or programs can get in or out. Windows comes with a built-in firewall which is well worth using. You may have firewall features built directly into your router or modem. And it may be worth looking at separate firewall programs produced by commercial firms.

The two main methods hackers use to figure out passwords mean there are a couple of important steps to choosing a password which will enhance your network security. The first step hackers take is to run an automated program which runs through all the words in the dictionary to see if they are right. This means you should avoid a password which is simply a word; it’s best to use a mix of letters and numbers. The second, more elaborate, hacking technique is to simply try every possible combination of numbers and letters. This means you should use the longest password possible: each extra digit makes your password at least 36 times more secure.

Another step you can take to improve your network security through passwords is to change passwords regularly. Even if there is only a tiny chance that somebody has figured out your password at any one moment, changing it reduces that chance back to zero. It’s also important to avoid using the same password in different situations as this increases the potential problems if your password is discovered.

Wireless network security is particularly important as it’s much easier to physically intercept data from such connections. Where you have the choice, use WPA2 encryption as this is the most secure method. If this isn’t available, prefer standard WPA over WEP unless WPA is not available. Make sure to turn off the wireless connection whenever you are not using it, particularly if you ever plug your laptop into a wired network. And when using a WiFi hotspot, check with staff to make sure you are connected to the genuine network rather than a bogus connection launched by nearby hackers.

For all the technical tricks hackers use to breach network security, half of all data losses are down to equipment being lost or stolen. As well as taking care to protect against this, you should consider encrypting any confidential data stored on a laptop or USB drive. There are several programs available which can protect your data from being accessed by unauthorized users. Some of these programs are open source and therefore free to use, though you should make sure to research and read credible reviews before deciding which to use.

What is a Command Prompt?

A command prompt is a text-based interface which allows someone to interact with an operating system via a command line, which allows the user to type commands and hit “enter” to execute them. Originally, all operating systems were text-based, requiring users to enter text commands to accomplish various tasks. In the 1980s, graphical user interfaces began to be developed, allowing users to interact with their operating systems in a way comparable to the way that most computer users operate today. Text-based operating systems, along with their command prompts, are still in use, and at the core of every graphical user interface, there is a command prompt.

In the case of a text-based system, being able to navigate with the command prompt is critical, because there is no other option. Users must learn the proper syntax for the system, along with the terminology accepted and understood by the command prompt. Numerous handbooks can be found for learning about various command prompt interfaces, and many experts in the computer field work with command prompts on a regular basis because they can allow for great power and flexibility.

Users of operating systems with graphic interfaces can still have reason to need a command prompt. For example, it is often easier to perform system diagnostics when there is a problem with the use of the command prompt. This tool can also be used for things like pinging and performing other tasks. Windows users can usually get to the command prompt by entering “cmd” into the “Run” box in the Start menu, or by going into the “Accessories” menu. Mac users can access their command prompt by going into “Terminal.”

People need to be careful when working within the command prompt, because it is very easy to make mistakes. The failsafes such as messages asking if a user really wants to do something are often not present, and people who are unfamiliar with the proper syntax and terminology to use can get into trouble and have difficulty navigating. It is also important to be aware that malicious and more experienced computer users may give out dangerous directions as pranks, so when someone provides a list of suggestions and command line shortcuts, it's a good idea to research them to confirm that they will perform the desired operations.

The easiest way to learn to work with the command line is through practice and regular use. Numerous guidelines can be found on the web for people who want examples of simple tricks and tips. Guidebooks are also published in hard copy version, and these guidebooks often contain a great deal of useful information which can help people gain experience.

What is a Network Operating System?

A network operating system (NOS) is a software program that controls other software and hardware that runs on a network. It also allows multiple computers, also known as network computers, to communicate with one main computer and each other, so as to share resources, run applications, and send messages, among other things. A computer network can consist of a wireless network, local area network (LAN), a wide area network (WAN), or even two or three computer networks. The heart of any of these networks, however, is the network operating system.

There are different types of operating systems. Most individual computer users run client operating systems, like Windows XP®, which run on a single computer. Personal computers that individuals use at home have a client operating system which manages the interactions and processes between the computer and its peripherals such as the keyboard, mouse, external monitor, and printer. In a sense, this is also a network, though it is different in scale than a network operating system which manages the interactions of many computers.

A network usually consists of many network computers that are connected to a central hub or router. The central hub, in turn, is connected to a larger, main computer. The network may also include other devices like printers, a tape-backup system, and a central storage facility. The main network computer runs all the connected computers and devices with the help of the operating system software.

A network administrator is the person who installs and manages the network and its operating system. He or she may configure the NOS to recognize a wireless network as well. If a WAN is involved, this would probably require more than one network administrator, as the network would likely be located offsite.

A network operating system has a menu-driven administration interface. From this interface, the network administrator may perform a variety of activities. He or she can use the interface to format hard drives, set up security restrictions, or establish log-in information for each user. The interface of a network operating system can also be used to attach shared printers to the network, or configure the system to automatically back data up on a daily basis.

An important component of a network is the file server. A file server is the device where data is stored for use by network computers. It can be a single computer or it can be a cluster of external hard drives hooked up in series to store data. A network operating system helps manage the flow of information between that file server and the network computers.

Examples of network operating systems include UNIX®, Windows 2000 Server ®, and Netware®. Each operating system runs differently, and as such has to be configured to perform the actions the network requires. A good knowledge of each operating system is necessary to work with them. Network administrators may need to be certified in order to manage particular network operating systems.

What is a Network Address?

A network address is simply a code used by computers as a means of identification. Just like getting information to and from your home requires the postal service to know the house number and street name, a network address accomplishes the same thing for a computer network. Without some way of passing along this information, the idea of the Internet would be almost useless.

Just like the postal service, a computer must know where it is sending information. The network address is a set of unique identifying sets of information that can be used to find the right destination. While many may have heard of such an identifier being used to crack identify theft schemes and other sorts of online crime, that is really just a small part of the overall importance of the address. Nearly all information will require this address.

There are a number of different ways a network address can be configured on a computer. The most common way is to use a protocol known as the Internet Protocol (IP). An address that uses this protocol may also be referred to as an IP address. The information for the IP address is contained in 32 bits. A computer will likely keep the same IP address at least while connected to the Internet, though it may also change periodically, and can be manually reset.

The other type of protocol is known as media access control (MAC). This type of network address has a little more involved simply because it uses 48 bits instead of 32. The information from a MAC number is very useful, and offers clues along the way about the origin of the computer and where it is currently located from a physical standpoint. The IP address can also offer some of these facts as well.

The network address may be used to track someone down who is wanted, but this happens very rarely. In most cases, getting the information as to the physical location of a computer is highly privileged. It will likely require some sort of warrant in order to get access to that type of information.

This ability to track the computer has led some to have security concerns about the amount of privacy a network address offers. While it may be possible for someone to learn who the Internet service provider is and even a city or town, getting any information more specific than that will be very difficult. Unless the consumer is doing something illegal, having a network address is likely nothing to worry about.

What are the Most Useful Network Commands?

The most useful network commands, of course, depends on what kind of network you are working on. There are two main families of networks, and we will deal with both of those here. The first family, the Unix or Linux family, is the oldest, with its origins back in the early days of computing, when the Unix system rose to dominance among all network operating systems. The second family, the Windows family, is in wide use these days as many network computers run a Windows-based operating system. Both have similar functions available to them, but the network commands that achieve these ends are different.

One of the network commands that many people may be aware of is the ping command. Both use the same basic syntax, that of ping [destination_address], but the options available to each are different. Ping is an easy way to see how long it takes one computer to communicate with another, which can be used for a number of different troubleshooting purposes, and so is one of the first network commands people learn when debugging networks. Options available include setting a manual timeout, setting a larger buffer size to send, and timestamping each hop as it is made.

Traceroute is another of the popular network commands, as it shows what the route a packet is taking from a source to a destination. This can be interesting to see, to get an idea how much a network connection travels, but can also be useful for finding where a connection is slowing down, as each host as it is listed also shows how long the packet took getting there. Traceroute is part of the core suite of network commands available to both Unix and Windows systems, although the options available for each to differ slightly.

When you’re logged into a system, especially a Unix system with many other users, one of the network commands most used is the finger command. Using the syntax finger [username] results in a chunk of information being displayed about another user logged into the system. This may include their real name, their contact information, their email address, and any additional information they have specified in a document in their user directory. Remotely the command can often be utilized by using the syntax finger [username]@[host].

The ssh command allows you to make a secured connection from the host you’re logged into to another computer. This may be used either from a local computer, through a shell, or while logged into another host to work through that computer. Many systems also allow for the use of ssh-keygen, which generates a number of authentication keys for the ssh protocol.

Many systems also allow for a whois command, which can be a useful and easy way to acquire information about a domain name. The whois command may return various information, but most people use it to find the IP address of the host that the domain name resolves to. The whois command may also be set up to query the whois database in order to return more comprehensive information about the domain, including when it was registered, and the contact information of whoever registered it, as well as technical and administrative contacts.

What are Free Domain Names?

Many people have seen advertisements on the internet for free domain names, which often seem too good to be true. After all, with most reputable companies offering domain names for $8 US Dollars (USD) to $15 USD, how can other companies be offering free domain names with no strings attached? The short answer is that they can’t: although many companies may claim to offer free domain names, in reality what they are doing is bundling a domain name with other services, which do cost money. This is a sense of free that is used in the case of “free gift with purchase.”

Domain names are regulated by the Internet Corporation for Assigned Names and Numbers, or ICANN. ICANN accredits certain Domain Name Registrars to sell the generic top-level domains, such as .com, .net, .org, and .mobi. Additional domains, which are country specific, such as .uk or .tv, are handled by the nation itself, which licenses its own Domain Name Registrars. Depending on the domain suffix involved, the fees that absolutely must be incurred by the Domain Name Registrar are different. Since the majority of domains sold are within the .com space, however, we will look at those.

If free domain names were to exist, at the very least a Domain Name Registrar would have to expect to be able to give away the domain names without any loss. In reality, however, whenever a Domain Name Registrar sells a domain name, they have to pay a $0.20 US Dollars (USD) fee to ICANN. Additionally, with .com domains, they must pay a maximum fee to VeriSign of $6.86 USD. At that price, it becomes easy to see why no Domain Name Registrar could sell a .com domain for any less than $7.06 USD without losing money. On the other hand, a very cheap Domain Name Registrar could sell a domain for something like $7.20 USD and still make a profit if the quantity of domains sold was large enough.

Of course, outside of the .com domain space, that pricing can be even lower and still be profitable. With ICANN’s $0.20 USD fee, a .info domain name could be sold for $1.99 USD and still have a strong profit. And many other domain spaces have similarly low overhead. Even with these, though, giving away free domain names would still result in a $0.20 USD loss per domain name for the company giving them away.

What allows free domain names to work is that the company bundles them with required packages a customer has to buy to get the domain name. If, for example, in order to receive your free domain you have to sign up for at least a year of hosting, where the hosting is $9.95 USD each month, then the Domain Name Registrar is making nearly $120 USD each year from your hosting fees, which means they can easily afford to give away a $7 USD domain name. Similarly, a company can sell a .com domain name for around $7.06 USD even without requiring users to buy additional packages, so long as they make those packages so visible that many customers will choose to buy them, helping to boost their overall profit margin.

What Is a Top Level Domain?

Under the Domain Name System (DNS) which is used to allow people to type in words rather than numeric web addresses to reach a particular website, a top level domain is the last part of a domain name, after the final dot. Here at wiseGEEK, for example, the top level domain is “com.” Top level domains fall into a number of different categories, depending on who is allowed to use them.

The DNS system was devised as Internet use expanded, and researchers realized that having to type in numerical addresses could be challenging for some users. Under this system, which is administered by the Internet Corporation for Assigned Names and Numbers (ICANN), users can type in words or assortments of characters which are easier to remember than strings of numbers. Each domain includes a top level, second level, and third level or subdomain.

The creation of domain names also allowed businesses to brand themselves more effectively. Instead of telling people interested in Volkswagon cars to go to a specific number address, for example, the company could tell customers to go to volkswagon.com. The DNS system is sometimes compared to the phone book, because it allows people to look up a person, product, or service by name, rather than having to remember the right number.

A web address such as www.wisegeek.com is considered a domain name. The first part of the address, the “www,” is the third level or subdomain.“wisegeek” is the second level, and the “com” is the top level domain. Individual domain owners can create multiple subdomains under their second level domain, such as the subdomain “example” in example.wisegeek.com. Many people refer to second level domains as “domain names” because people often reference sites by the second level domain alone. However, multiple sites could have the same second level and different top level domains, which makes it important to spell out a domain name in full to avoid confusion.

Top level domains such as “com,” “org,” and “net” are generic. Anyone can register domain names in any of these top level domains. Some other generic top level domain options like “edu,” “gov,” and “mil” are restricted to people who can prove that they have a legitimate reason to use them. Top level domains sorted by country code, such as “ie” for Ireland, are also available, as are sponsored domains controlled by various industries.

When someone wants to register a new domain name, he or she has a choice of top level domain, assuming that those domain names are not already taken, and that he or she is authorized to use a particular domain. Some people like to get creative with top level domain names, as in the case of the social bookmarking site Delicious, which registered the domain icio.us so that it could create the subdomain “del” and spell out del.icio.us with its domain name.

What is Domain Registration?

Domain registration is the process by which a company or individual can secure a website domain, such as www.yoursite.com. Once you have completed domain registration the domain becomes yours for the period of the contract, usually one year. Before registration expires it must be renewed, or the domain reverts back to being available to the general public.

The Internet Corporation for Assigned Names and Numbers (ICANN) manages the international Domain Name Server (DNS) database. ICANN insures that all registered names are unique and map properly to a unique Internet Protocol (IP) address. The IP address is the numerical address of the website that tells other computers on the Internet where to find the server host and domain.

Domain registration is available to the public via a registrar. Fees and services vary from company to company, but the process is generally inexpensive. Before a domain registration can be approved, the new name must be checked against existing names in the DNS database. The online registrar provides a field into which you can enter your desired name and hierarchy —- that is, the letters that come after the "dot." Familiar hierarchies are .com, .net, .org, .name, .info and .biz. If the name is not already taken, it is available for domain registration.

During the domain registration process, you will be required to give contact information that will be publicly available through the WHOIS database. Anyone can go to a WHOIS search engine and enter a domain name to see who has registered it. Registrars require that this information be accurate and true. If you feel uncomfortable providing personal information, there are some registrars that will act as your proxy, supplying their information in place of your own as the contact for the domain. There may be a small fee for this service and potential drawbacks to balance against the ability to maintain your privacy, so read the Terms and Conditions carefully before deciding to opt for a domain by proxy.

Also important, be sure you will own the domain name, as some registrars maintain control over the domains they register. And be sure you retain the option to transfer the domain to another registrar, if you wish. There might be an initial period after which this becomes possible. Look for any fees that might be incurred as a result of transferring the domain. This could become important down the road if you wish to take advantage of another registrar's products or services.

Upon completing the domain registration process, it will take a period of hours to a few days to be able to see the domain online. The domain can be "parked" with an "in construction" page that acts as a kind of placeholder. Parking a domain is very inexpensive and most registrars offer this service for a small fee to give you time to come up with content. Once a registrant is ready to supply content, a web server must host the domain. The registrar might also provide hosting services, or you may wish to transfer your domain to another web hosting company.

If you are considering domain registration, ICANN recommends dealing with an accredited registrar. These registrars have entered into an official agreement with ICANN to meet minimal requirements for providing domain registration. For more information about domain registration, and for a list of accredited registrars, see the ICANN site.