RAM is an abbreviation for Random Access Memory. This is a sort of computer memory, that, unlike other storage devices including hard disk drives or DVDs, allows the information to be accessed directly without reading the previous content stored within it. Each time a program is launched, it is stored inside the RAM, because it could be accessed considerably faster than if it was read from another media device. With regards to the hosting service itself, extra RAM means that more web apps can work concurrently on a certain web server, particularly if they are resource-demanding and are accessed by a large number of people simultaneously. Unlike a shared web hosting plan in which the system resources of a certain account may be flexible and quite often depend on what other users consume also, a VPS features a guaranteed amount of RAM you can use all the time. That memory is allotted to one hosting server only and won't be used by other customers even in case it's not in use.