RAM, which is short for Random Access Memory, is a computer storage media which is accessed much quicker than a disk drive, due to the fact that the info can be read randomly, skipping the bytes before the needed information is reached. On a 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'll be able to run at the same time and the more people will be able to browse your websites without any effect on the site’s/server’s overall performance. Unlike a disk drive, however, the RAM is used for short-term 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 your scripts could use may be limited and can change according to what the some other clients on the same machine use. With a virtual or a dedicated hosting server, alternatively, you shall have a set amount of RAM that will not be used by anyone else even if you do not use it at a given time.