RAM is an abbreviation for Random Access Memory. This is a kind of computer memory, which, different from other storage devices such as hard disk drives or DVDs, permits the info to be accessed directly without reading the previous content stored within it. Anytime an application is started, it's stored inside the RAM, due to the fact that it may be accessed considerably faster than if it was read from another media. With regard to the website hosting service itself, extra RAM means that more web apps can run simultaneously on a certain web server, especially when they're resource-demanding and are accessed by a significant number of people simultaneously. Different from a shared web hosting plan where the resources of a particular account may be flexible and quite often depend on what other users consume as well, a VPS includes a guaranteed amount of RAM which can be used all the time. That memory is assigned to one web server only and shall not be used by other clients even in case it's not used.