RAM, that stands for Random Access Memory, is a computer storage media which is accessed much quicker than a disk drive, due to the fact that the data can be read randomly, skipping the bytes before the needed data is reached. On a server, the RAM is employed to load scripts and web apps when they are executed, so the more RAM you are able to use, the more programs you will be able to run at the same time and the more people shall be able to check out your websites without any effect on the site’s/server’s general performance. Unlike a disk drive, however, the RAM is employed for non permanent storage purposes, because the data is lost when the power is shut off. In case you use a shared web hosting account, the physical memory that your scripts could use may be limited and may change based on what the other customers on the same hosting server use. Through a virtual or a dedicated server, on the other hand, you'll have a set amount of RAM which won't be used by others even when you don't use it at a particular time.