Alternatively referred to as main memory, primary memory, or system memory, Random Access Memory (RAM) is a computer storage location that allows information to be stored and accessed quickly from random locations within DRAM on a memory module. Because information is accessed randomly instead of sequentially like a CD or hard drive the computer is able to access the data much faster than it would if it was only reading the hard drive. However, unlike ROM and the hard drive RAM is a volatile memory and requires power in order to keep the data accessible, if power is lost all data contained in memory lost.
As the computer loads parts of the operating system and drivers are loaded into memory, which allows the CPU to process the instructions much faster and your computer to load faster. After the operating system has loaded, each program you open such as the browser you're using to view this page is loaded into memory while it is running. If too many programs are open the computer will swap the data in the memory between the RAM and the hard disk drive.
Over the evolution of computers there has been several different variations of RAM used in computer. Some of the more common examples are DIMM, RIMM, SIMM, SO-DIMM, and SOO-RIMM. Below is an example image of a 512MB DIMM computer memory module and what the typical desktop computer memory card will look like. This memory module would be installed into memory slots on the motherboard.
Tip: New users often confuse memory (RAM) with disk drive space. See our memory definition for a comparison between memory and storage.
Related RAM pages
- Computer memory help and support.
- Computer RAM diagram.
- Determining how much RAM is installed and available.
- What is the difference between RAM and ROM?
- Installing PC computer memory (RAM).