RAM is an abbreviation for Random Access Memory. This is a type of computer memory, which, in contrast to other storage devices including harddrives or DVDs, permits the information to be accessed directly without reading the previous content stored in it. Each time an application is launched, it's stored in the RAM, due to the fact that it may be accessed much more quickly than if it was read from another media. With regards to the hosting service itself, additional RAM means that more web applications can work all at once on a particular hosting server, especially if they're resource-demanding and are accessed by a significant number of people at the same time. In contrast to a shared web hosting solution where the system resources of a certain account can be flexible and often depend on what other users consume also, a VPS offers a guaranteed amount of RAM that can be used all the time. That memory is assigned to one web server only and won't be used by other customers even if it is not being used.