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, allows the information to be accessed directly without reading the previous content saved in it. Each time a program is launched, it is stored inside the RAM, since it could be accessed much faster than if it was read from another media. In terms of the web hosting service itself, extra RAM means that more web applications can operate at the same time on a particular web server, particularly if they are resource-demanding and are accessed by a large amount of people at the same time. In contrast to a shared web hosting package in which the resources of a particular account can be flexible and often depend on what other end users consume as well, a VPS features a guaranteed amount of RAM that can be used all the time. That memory is assigned to one hosting server only and shall not be used by other customers even when it's not in use.