RAM is an abbreviation for Random Access Memory. This is a sort of computer memory, that, different from other storage devices such as harddrives or DVDs, permits the info to be accessed directly without reading the previous content stored in it. Whenever an application is started, it is stored within the RAM, as it could be accessed considerably quicker than if it was read from another media. With regard to the web hosting service itself, extra RAM means that more web applications can operate simultaneously on a given server, particularly if they're resource-demanding and are accessed by a large amount of people at the same time. Not like a shared web hosting package where the resources of a particular account can be flexible and often depend on what other end users consume too, a VPS offers a guaranteed amount of RAM which can be used all the time. That memory is allotted to one web server only and will not be used by other clients even in case it is not used.