Random-access memory (RAM) is a form of computer data storage is an integrated circuit which allow stored data to be accessed in random order. It is a volatile types of memory where the information is lost after the power is switched off.

Similar to a microprocessor, RAM is a memory chip with integrated circuit (IC) made of millions of transistors and capacitors. In the most common form of computer memory, dynamic random access memory (DRAM), a transistor and a capacitor are paired to create a memory cell, which represents a single bit of data.

The capacitor holds the bit of information 0 or 1. The transistor acts as a switch that lets the control circuitry on the memory chip read the capacitor or change its state.

­A capacitor is able to store electrons. To store 1 in the memory cell, the capcitor is filled with electrons. To store 0, it is emptied. The problem with the capacitor is that it has a leak and in a few milliseconds can become empty. Therefore, for dynamic memory to work, either the CPU or the memory controller has to recharge all of the capacitors holding 1 before they discharge. To do this, the mem­ory controller reads the memory and then writes it right back. This refresh operation happens automatically thousands of times per second.­