RAM is an abbreviation for Random Access Memory. This is a sort of computer memory, which, in contrast to other storage devices such as hard disk drives or DVDs, enables the data to be accessed directly without reading the previous content stored inside it. Anytime a program is launched, it's stored inside the RAM, as it could be accessed considerably quicker than if it was read from another media device. In terms of the web hosting service itself, additional RAM means that more web apps can run simultaneously on a particular web server, especially when they're resource-demanding and are accessed by a great number of of people simultaneously. Not like a shared web hosting plan where the system resources of a given account can be flexible and frequently depend on what other end users consume as well, a VPS includes a guaranteed amount of RAM you can use at all times. That memory is allocated to one server only and will not be used by other customers even when it's not in use.