RAM is an abbreviation for Random Access Memory. This is a sort of computer memory, that, different from other storage devices such as hard disk drives or DVDs, allows the information to be accessed directly without reading the previous content stored within it. Every time a program is started, it is stored inside the RAM, because it can be accessed much faster than if it was read from another media device. In terms of the web hosting service itself, more RAM means that more web applications can work simultaneously on a particular web server, particularly if they're resource-demanding and are accessed by a significant number of people all at once. In contrast to a shared web hosting package where the system resources of a particular account may be flexible and sometimes depend on what other users consume as well, a VPS includes a guaranteed amount of RAM which you can use all the time. That memory is allotted to one web server only and won't be used by other clients even when it is not used.