RAM is an abbreviation for Random Access Memory. This is a type of computer memory, which, different from other storage devices including harddrives or DVDs, allows the info to be accessed directly without reading the previous content stored inside it. Anytime an application is launched, it's stored within the RAM, due to the fact that it may be accessed considerably quicker than if it was read from another media device. With regard to the hosting service itself, additional RAM means that more web applications can work at the same time on a given hosting server, especially if they are resource-demanding and are accessed by a great number of of people concurrently. Different from a shared web hosting package in which the resources of a particular account can be flexible and sometimes depend on what other end users consume also, a VPS offers a guaranteed amount of RAM which you can use always. That memory is allotted to one hosting server only and won't be used by other clients even in case it's not being used.