RAM is an abbreviation for Random Access Memory. This is a type of computer memory, which, different from other storage devices like hard disk drives or DVDs, allows the info to be accessed directly without reading the previous content located inside it. Each time an app is started, it is stored within the RAM, due to the fact that it may be accessed considerably quicker than if it was read from another media. With regards to the hosting service itself, additional RAM means that more web applications can work at the same time on a particular server, particularly when they are resource-demanding and are accessed by a large number of people at the same time. Different from a shared web hosting solution in which the system resources of a particular account may be flexible and sometimes depend on what other end users consume too, a VPS offers a guaranteed amount of RAM which can be used always. That memory is allocated to one web server only and will not be used by other customers even when it's not being used.