RAM is an abbreviation for Random Access Memory. This is a type of computer memory, which, different from other storage devices such as harddrives or DVDs, enables the data to be accessed directly without reading the previous content saved inside it. Anytime an application is started, it is stored in the RAM, as it can be accessed much more quickly than if it was read from another media. In terms of the website hosting service itself, additional RAM means that more web applications can operate concurrently on a certain server, particularly when they're resource-demanding and are accessed by a great number of of people concurrently. Not like a shared web hosting solution in which the resources of a given account can be flexible and frequently depend on what other end users consume too, a VPS includes a guaranteed amount of RAM you can use always. That memory is allotted to one server only and won't be used by other customers even if it is not used.