RAM, which refers to Random Access Memory, is a computer storage media that could be accessed considerably faster than a hard drive, simply because the information can be read randomly, skipping the bytes before the needed info is reached. On a hosting server, the RAM is employed to load scripts and web apps when they are executed, so the more RAM you can use, the more programs you'll be able to run at the same time and the more people shall be able to browse your Internet sites without any effect on the site’s/server’s performance. In contrast to a disk drive, however, the RAM is employed for temporary storage purposes, because the information is lost as soon as the power is shut off. If you use a shared web hosting account, the physical memory your scripts can use may be limited and might change depending on what the some other clients on the same machine use. Using a virtual or a dedicated hosting server, alternatively, you will have a guaranteed amount of RAM which won't be used by others even when you do not use it at a particular time.