RAM, that refers to Random Access Memory, is a computer storage media which is accessed faster than a hard disk drive, because the data can be read randomly, skipping the bytes before the needed data is reached. On a hosting server, the RAM is used to load scripts and web apps after they are executed, so the more RAM you may use, the more applications you'll be able to run concurrently and the more people will be able to check out your Internet sites without any effect on the site’s/server’s overall performance. In contrast to a disk drive, however, the RAM is employed 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 which your scripts are able to use may be limited and might change according to what the some other clients on the same machine use. With a virtual or a dedicated web server, alternatively, you will have a fixed amount of RAM that won't be used by others even when you do not use it at a certain time.