RAM is an abbreviation for Random Access Memory. This is a type of computer memory, that, in contrast to other storage devices such as hard disk drives or DVDs, permits the info to be accessed directly without reading the previous content stored inside it. Anytime a program is started, it is stored within the RAM, because it may be accessed much faster than if it was read from another media device. With regard to the hosting service itself, additional RAM means that more web apps can operate concurrently on a given hosting server, especially if 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 system resources of a certain account may be flexible and sometimes depend on what other users consume also, a VPS provides a guaranteed amount of RAM which can be used at all times. That memory is allotted to one server only and shall not be used by other customers even when it is not being used.