RAM is an abbreviation for Random Access Memory. This is a type of computer memory, which, different from other storage devices like hard disks or DVDs, enables the data to be accessed directly without reading the previous content saved within it. Whenever a program is launched, it's stored in the RAM, due to the fact that it could be accessed much faster than if it was read from another media. With regard to the website hosting service itself, additional RAM means that more web apps can operate simultaneously on a particular hosting server, especially if they're resource-demanding and are accessed by a large number of people all at once. In contrast to a shared web hosting plan where the resources of a given account could be flexible and often depend on what other users consume also, a VPS provides a guaranteed amount of RAM which you can use always. That memory is assigned to one hosting server only and will not be used by other customers even when it is not in use.