RAM, that 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 data is reached. On a web server, the RAM is employed to load scripts and web programs when they are executed, so the more RAM you are able to use, the more programs you shall be able to run simultaneously and the more people will be able to browse your websites without effect on the site’s/server’s overall performance. Unlike a disk drive, however, the RAM is used for temporary storage purposes, since the information is lost once the power is shut off. If you use a shared web hosting account, the physical memory that your scripts may use may be limited and can change according to what the some other clients on the same web server use. Using a virtual or a dedicated server, however, you shall have a fixed amount of RAM that won't be used by anyone else even if you don't use it at a given time.