RAM is an abbreviation for Random Access Memory. This is a type of computer memory, which, in contrast to other storage devices such as hard disks or DVDs, enables the info to be accessed directly without reading the previous content saved within it. Anytime a program is started, it's stored inside the RAM, because it can be accessed considerably quicker than if it was read from another media device. With regards to the web hosting service itself, extra RAM means that more web applications can run at the same time on a given web server, particularly if they are resource-demanding and are accessed by a significant number of people simultaneously. Not like a shared web hosting plan in which the resources of a given account can be flexible and sometimes depend on what other end users consume also, a VPS provides a guaranteed amount of RAM which you can use all the time. That memory is allotted to one hosting server only and shall not be used by other customers even in case it's not in use.