RAM is an abbreviation for Random Access Memory. This is a type of computer memory, that, different from other storage devices such as harddrives or DVDs, permits the data to be accessed directly without reading the previous content saved within it. Whenever an app is started, it is stored within the RAM, because it can be accessed considerably quicker than if it was read from another media. With regards to the website hosting service itself, more RAM means that more web apps can work concurrently on a particular hosting server, particularly if they are resource-demanding and are accessed by a great number of of people simultaneously. Unlike a shared web hosting package where the system resources of a certain account can be flexible and sometimes depend on what other users consume too, a VPS offers 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 when it is not in use.