CPU, or Central Processing Unit, is that part of a home PC or a hosting server which runs all of the calculations. Every CPU functions at a certain speed and the higher it is, the sooner everything shall be processed, so in case you host resource-demanding web apps on a web server, for instance, a powerful processor will allow them to be executed faster, which will considerably contribute to the overall user experience. The new generations of CPUs have 2 and more cores, each one functioning at a certain speed to ensure a superior and faster performance. This type of architecture enables the processor to manage numerous processes concurrently or a number of cores to manage 1 process if it needs more computing power to be executed. Needless to say, other variables including the amount of RAM or the connection a particular web server uses could also affect the performance of the sites hosted on it.