Random access memory (RAM)--an essential component for running personal computers--determines the computer's speed. Computers possess five key functions: input, output, processing, storage and retrieval. RAM is designed for storage and retrieval functions. RAM provides a location for a computer's central processing unit (CPU) to access current information. Typically, RAM is referred to as a computer's memory. The physical structure of RAM provides some advantages and disadvantages. RAM has several characteristics that distinguish it from other storage types.
The Structure of RAM
RAM is composed of transistors and capacitors. Transistors act as switches, while capacitors store information. Transistors and capacitors are paired and create a memory cell. Each memory cell can hold one bit of information. The capacitor loses information quickly and the central processing unit (CPU) must read the information and write the information back. As a result, you can consider RAM short-term memory. Information is stored in RAM to facilitate the transfer of information to long-term memory or to run applications and programs.
Computer memory is either volatile or non-volatile. Compared to the human mind, volatile memory is short-term while non-volatile memory is long-term. Volatile memory requires a power source to maintain the stored information. Non-volatile memory is not limited by power restrictions and retains information for extended time periods. RAM is volatile memory and, as a result, serves as a short-term storage location. The central processing unit (CPU) accesses information stored in RAM in random order so you can work with several programs simultaneously.
Types of Data Storage
Computers use RAM to store information about currently running applications, documents and data. For example, while you are using word processing software, your CPU stores data to RAM each time you type and during auto-save. Once you are finished and save the file to a location, the information is moved to a long-term storage option like your hard disk.