RAM, which is short for Random Access Memory, is a computer storage media that is accessed considerably quicker than a hard disk, simply because the info can be read randomly, skipping the bytes before the needed info is reached. On a hosting server, the RAM is used to load scripts and web applications after they are executed, so the more RAM you are able to use, the more apps you'll be able to run concurrently and the more people will be able to look through your Internet sites with no effect on the site’s/server’s performance. Different from a disk drive, however, the RAM is used for temporary storage purposes, as the data is lost as soon as the power is shut off. If you use a shared web hosting account, the physical memory your scripts are able to use may be limited and could change according to what the some other clients on the same web server use. Using a virtual or a dedicated server, however, you will have a guaranteed amount of RAM that won't be used by anybody else even if you don't use it at a certain time.