RAM is an abbreviation for Random Access Memory. This is a kind of computer memory, that, in contrast to other storage devices including hard disk drives or DVDs, allows the info to be accessed directly without reading the previous content saved inside it. Each time an application is started, it is stored in the RAM, since it could be accessed much faster than if it was read from another media. In terms of the hosting service itself, more RAM means that more web apps can run simultaneously on a certain web server, particularly when they are resource-demanding and are accessed by a large number of people concurrently. In contrast to a shared web hosting plan where the system resources of a particular account could be flexible and often depend on what other users consume too, a VPS provides a guaranteed amount of RAM you can use always. That memory is assigned to one hosting server only and won't be used by other clients even in case it is not in use.