CPU, or Central Processing Unit, is that part of a computer or a hosting server that executes all of the calculations. Each CPU runs at a certain speed and the higher it is, the swifter everything shall be processed, so when you host resource-demanding web applications on a web server, for example, a powerful processor shall allow them to be performed quicker, which will drastically contribute to the whole user experience. The modern generations of CPUs have 2 and more cores, each working at a certain speed to ensure a much better and speedier performance. This kind of architecture makes it possible for the processor to handle a variety of processes concurrently or several cores to manage one process if it requires extra computing power in order to be executed. Naturally, other variables such as the amount of RAM or the connection a given web server uses can also affect the overall performance of the sites hosted on it.