RAM is an abbreviation for Random Access Memory. This is a sort of computer memory, which, in contrast to other storage devices like harddrives or DVDs, enables the info to be accessed directly without reading the previous content stored within it. Each time an application is launched, it's stored within the RAM, as it could be accessed considerably faster than if it was read from another media device. With regards to the hosting service itself, more RAM means that more web applications can run all at once on a certain hosting server, especially if they are resource-demanding and are accessed by a large amount of people simultaneously. Different from a shared web hosting solution in which the resources of a given account may be flexible and frequently depend on what other users consume too, a VPS offers a guaranteed amount of RAM that can be used always. That memory is assigned to one web server only and shall not be used by other clients even in case it is not in use.