RAM is an abbreviation for Random Access Memory. This is a kind of computer memory, which, in contrast to other storage devices including hard disk drives or DVDs, permits the data to be accessed directly without reading the previous content located within it. Every time an application is started, it's stored in the RAM, because it can be accessed much more quickly than if it was read from another media device. With regards to the hosting service itself, more RAM means that more web apps can run simultaneously on a particular server, especially if they are resource-demanding and are accessed by a significant number of people concurrently. Unlike a shared web hosting plan where the resources of a certain account could be flexible and quite often depend on what other end users consume as well, a VPS includes a guaranteed amount of RAM that can be used always. That memory is assigned to one hosting server only and shall not be used by other clients even if it is not being used.