What is a Web Server?
The term ‘web server’ can refer to two things: Either a piece of computer software that accepts requests from clients and serves them HTTP responses, or a piece of hardware which runs this software program. This article discusses a web server in reference to the hardware.
The components of a web server are very similar to those of a desktop computer found in many homes around the world. Using the correct software, a home computer could in theory act as a web server, though it is never as simple as that. Servers have a CPU, RAM, a hard drive and Internet connections, in exactly the same way as desktop computers do. The key differences lie in the specifications.
Servers do not have high-end graphics requirements, and as a result do not have high speed CPU’s. Instead they often consist of more than one CPU grouped together, rather than a single, high-speed CPU. Memory sizes are also usually similar to those of home computers, but this can vary depending on what the server is being used for. Servers tend to have more than one hard drive, and these are of large capacities. They also have more than one power supply, which gives them back-up in the event of power failure. With reliability an important factor, the components of a server are produced to an extremely high standard, and are regularly upgraded to enhance performance.
Web hosting companies mount many servers together, housing them in racks. The most common types in use over the last few years are known as ‘blade servers’, and are essentially stripped-down computers – with the key components such as the memory, processors, input connections and output connections all housed together, and the power supplied externally through an enclosure. This reduces the amount of unnecessary components, thus saving the web hosting company both space and money.
All of these servers are housed together in a data center. Due to the fact the servers are running constantly, they can get extremely hot, and as a result need to be cooled at 65-70C in order to keep them performing optimally. Over-heating servers may not perform as well, and can even crash – causing no end of problems for the web host and their customers. The data center will also have several power supplies, stand-by generators, fire detection facilities and a number of technicians working around the clock to make sure the servers are running smoothly and doing what is required of them.