RAM is an abbreviation for Random Access Memory. This is a type of computer memory, which, in contrast to other storage devices like hard disk drives or DVDs, permits the info to be accessed directly without reading the previous content stored within it. Each time a program is started, it is stored in the RAM, since it can be accessed much quicker than if it was read from another media device. In terms of the website hosting service itself, additional RAM means that more web applications can run all at once on a given web server, especially when they are resource-demanding and are accessed by a significant number of people concurrently. In contrast to a shared web hosting solution where the system resources of a particular account could be flexible and often depend on what other users consume also, a VPS has a guaranteed amount of RAM which you can use always. That memory is allocated to one server only and shall not be used by other customers even if it's not used.