RAM is an abbreviation for Random Access Memory. This is a sort of computer memory, which, different from other storage devices such as hard disks or DVDs, enables the information to be accessed directly without reading the previous content saved within it. Every time an application is started, it's stored in the RAM, as it can be accessed much more quickly than if it was read from another media. With regard to the website hosting service itself, more RAM means that more web apps can run simultaneously on a given hosting server, particularly if they are resource-demanding and are accessed by a great number of of people at the same time. In contrast to a shared web hosting solution where the resources of a certain account can be flexible and often depend on what other users consume as well, a VPS has a guaranteed amount of RAM which you can use always. That memory is allotted to one hosting server only and will not be used by other clients even if it is not used.