RAM, which refers to Random Access Memory, is a computer storage media which could be accessed much quicker than a hard disk, as the info can be read randomly, skipping the bytes before the needed information is reached. On a server, the RAM is used to load scripts and web applications once they are executed, so the more RAM you can use, the more applications you shall be able to run simultaneously and the more people will be able to look through your websites without effect on the site’s/server’s functionality. Different from a disk drive, however, the RAM is employed for temporary storage purposes, as the info is lost once the power is shut off. When you use a shared web hosting account, the physical memory that your scripts may use may be limited and could change based on what the some other clients on the same machine use. Through a virtual or a dedicated server, on the other hand, you'll have a guaranteed amount of RAM that won't be used by anyone else even if you do not use it at a certain time.