RAM is an abbreviation for Random Access Memory. This is a kind of computer memory, that, unlike other storage devices such as harddrives or DVDs, enables the data to be accessed directly without reading the previous content saved within it. Every time an application is launched, it's stored within the RAM, due to the fact that it could be accessed considerably quicker than if it was read from another media. In terms of the web hosting service itself, more RAM means that more web apps can run simultaneously on a given hosting server, especially if they're resource-demanding and are accessed by a great number of of people all at once. Not like a shared web hosting plan in which the system resources of a certain account could be flexible and sometimes depend on what other users consume also, a VPS features a guaranteed amount of RAM you can use all the time. That memory is assigned to one hosting server only and won't be used by other customers even when it's not in use.