Any device that holds data for a computer for a short period of time is called computer memory. If you have spent even just a little time with any computer, you will hear about RAM, Hard Disks, or CD's and DVD's. All these are means to store the information from a computer. The capacity and speed of storage varies much in these kinds of memory. The Central Processing Unit of a computer is connected to the main memory. This main memory component is useful in storing the data and programs that are currently being run in the CPU. In modern computers the random access memory (RAM), a solid-state memory, is attached to the CPU using a memory bus. A memory bus is also called an address bus.

In addition to RAM, there may be a cache memory also, which contains small chunks of information that is to be used by the CPU soon. The idea is to reduce the fetching time, and thereby speed up the working of the CPU. Cache memory increases the throughput of the CPU, affecting the performance of the computer. In general, the RAM is the most important part of computer memory. RAM is made from integrated semiconductor chips. RAM and Other Types of Memory: The primary characteristic that separates RAM from other types of memory is the fact that any memory location RAM can be accessed at almost the same speed in a random manner. This is vastly different from the accessing approach used in other devices like the sequential one, used in tapes etc. Some RAM chips are volatile, meaning that as soon as the power supply is switched off to these chips, they lose all the data.