Random Access Memory (RAM), also known as main memory, is an internal memory that exchanges data directly with the CPU. It can be read and written at any time (except during refresh), and it is very fast, often serving as a temporary data storage medium for operating systems or other running programs. When RAM is working, it can write (store) or read (fetch) information from any specified address at any time. The biggest difference between RAM and ROM is the volatility of data, meaning that once the power is turned off, the stored data will be lost. RAM is used in computers and digital systems to temporarily store programs, data, and intermediate results.