A server is basically a computer dedicated to provide different services to other computers. It is a computer program or a device that provides functionality for other programs or devices, called "clients". Servers can provide various functionalities, often called "services", such as sharing data or resources among multiple clients, or performing computation for a client. A single server can serve multiple clients, and a single client can use multiple servers.
Hopefully a peep at servers based on functionality and hardware can help you choose the server that is right for you.
Different servers have different purposes. The most common types of servers are;
Application servers provide a wide range of applications to other computers on a LAN or WLAN network. For most companies, this might mean just one type of application, or it can be several applications, like imaging, word processing, or even security applications that keep the network safe.
Mail servers are responsible for sending, receiving, relaying, and storing e-mails. Microsoft Exchange server is one of the most common types of servers today, especially among corporate users.
Web servers are probably the most common type of server encountered. Simply, it is a server that hosts websites, and thus it must be connected to the Internet 24/7. People who own a small business or personal site usually rent space from web hosting companies, rather than purchase their own. However, large businesses that may experience a lot of traffic on a regular basis find it more efficient to purchase their own dedicated web servers.
Database servers provide data and database services to client computers. This type of server delivers a variety of tasks, such as data storage, manipulation, analysis, archiving, and almost any type of non-user-specific task that has to do with data.
File servers are computers that store files and provide access to them at the client computer's request. This type of server can be dedicated or non-dedicated. Dedicated file servers are exclusively used just to store and access data, while non-dedicated ones can also share the function of other types of servers.
Home servers, as the name implies, are servers for home use. These days, many people own multiple computers and devices at home, and want to do activities beyond typing and searching the Internet, such as stream movies, share files and resources, and store (and backup) pictures, movies, and music files. These types of servers can do these things and more, and are usually geared towards the everyday user that just wants a simple plug-and-play machine to enhance the personal computing experience at home.
If you are setting up your own data center, you will need to decide which type of server you prefer. The three main types of servers are: towers, racks, and blades.
The most basic kind of servers on the market are tower servers. You probably recognize towers, as they look very similar to desktop PCs. they are ideal for small, remote or branch office environments, and offer maximum in-chassis flexibility and all-inclusive server/storage solutions. If space is not a concern, you can usually get more drives and more hardware into a single tower.
Racks are designed to hold multiple servers, and rack servers are specially constructed to fit in these small spaces. They are essentially stacked right on top of each other, which does make cooling more difficult, while scaling is much easier. A rack server is good for buyers who want to maximize the available space in a data center, and need flexibility to combine servers that perform different duties. These servers are better for a medium sized business or a small one that is well experienced with using servers.
Blade servers are the most compact of the three types of server. Although they are very similar to rack servers in design, some components have been removed from blade servers and are instead shared among multiple ones. This makes blade servers even thinner. This type of server has a number of advantages because it saves both power and space while providing more processing power. They are ideal for data centers and use with external storage, and offer maximum computing power in space, power and cooling saving designs. This is a higher end server that is well suited for a business that needs a lot of computing power.
Ultimately, the type of server you choose depends on your needs. If space is your main concern, you may opt for racks. If cooling will be a problem but not space, you may choose towers. If money is not a problem and you need space and consolidation, blades are the way to go.