RAM, that refers to Random Access Memory, is a computer storage media which is accessed considerably quicker than a hard disk, as the data can be read randomly, skipping the bytes before the needed data is reached. On a web server, the RAM is used to load scripts and web applications after they are executed, so the more RAM you may use, the more apps you'll be able to run simultaneously and the more people will be able to explore your Internet sites without any effect on the site’s/server’s performance. In contrast to a disk drive, however, the RAM is used for short-term storage purposes, due to the fact that the info is lost the moment the power is shut off. If you use a shared web hosting account, the physical memory your scripts could use may be limited and can change based upon what the some other clients on the same hosting server use. With a virtual or a dedicated hosting server, however, you will have a fixed amount of RAM which will not be used by others even if you don't use it at a certain time.