RAM is an abbreviation for Random Access Memory. This is a sort of computer memory, that, in contrast to other storage devices such as hard disk drives or DVDs, permits the data to be accessed directly without reading the previous content located inside it. Anytime an app is launched, it's stored within the RAM, as it can be accessed considerably quicker than if it was read from another media. In terms of the website hosting service itself, extra RAM means that more web apps can run simultaneously on a given hosting server, particularly if they are resource-demanding and are accessed by a great number of of people concurrently. Different from a shared web hosting solution in which the system resources of a given account may be flexible and quite often depend on what other end users consume too, a VPS has a guaranteed amount of RAM that can be used always. That memory is allocated to one hosting server only and won't be used by other customers even in case it is not used.