RAM, that refers to Random Access Memory, is a computer storage media that may be accessed considerably quicker than a hard disk drive, due to the fact that the info can be read randomly, skipping the bytes before the needed information is reached. On a web server, the RAM is employed to load scripts and web apps once they are executed, so the more RAM you can use, the more applications you will be able to run simultaneously and the more people will be able to surf your sites without effect on the site’s/server’s performance. Different from a disk drive, however, the RAM is employed for short-term storage purposes, due to the fact that the info is lost when the power is shut off. In case you use a shared web hosting account, the physical memory your scripts are able to use may be limited and can change depending on what the some other clients on the same hosting server use. With a virtual or a dedicated web server, however, you'll have a fixed amount of RAM which will not be used by anyone else even when you do not use it at a given time.