RAM is an abbreviation for Random Access Memory. This is a kind of computer memory, that, unlike other storage devices including hard disk drives or DVDs, permits the data to be accessed directly without reading the previous content stored in it. Each time an application is started, it is stored inside the RAM, due to the fact that it can be accessed considerably faster than if it was read from another media. In terms of the website hosting service itself, more RAM means that more web applications can work simultaneously on a particular server, particularly when they are resource-demanding and are accessed by a large number of people simultaneously. In contrast to a shared web hosting plan in which the resources of a particular account may be flexible and quite often depend on what other users consume too, a VPS has a guaranteed amount of RAM you can use always. That memory is allotted to one web server only and won't be used by other customers even when it's not being used.