RAM is the most common type of memory found in computers and other devices, such as printers. RAM is an acronym for random access memory, a type of computer memory that can be accessed randomly. In common usage, the term RAM is synonymous with main memory, the memory available to programs. Computer RAM is a form of computer data storage. Today, it takes the form of integrated circuits that allow stored data to be accessed in any order with a worst case performance of constant time. RAM is often associated with volatile types of memory (such as DRAM memory modules), where its stored information is lost if the power is removed. Many other types of non-volatile memory are RAM as well, including most types of ROM and a type of flash memory called NOR-Flash. The first RAM modules to come into the market were created in 1951 and were sold until the late 1960s and early 1970s. Computer RAM is classified mainly into Static RAM or SRAM and Dynamic RAM or DRAM. In static RAM, a bit of data is stored using the state of a flip-flop. This form of RAM is more expensive to produce, but is generally faster and requires less power than DRAM and, in modern computers, is often used as cache memory for the CPU. DRAM stores a bit of data using a transistor and capacitor pair, which together comprise a memory cell. The capacitor holds a high or low charge (1 or 0, respectively), and the transistor acts as a switch that lets the control circuitry on the chip read the capacitor's state of charge or change it. As this form of memory is less expensive to produce than static RAM, it is the predominant form of computer memory used in modern computers. ECC memory, which can be either SRAM or DRAM, includes special circuitry to detect and/or correct random faults in the stored data, using parity bits or error correction code.In general, the term RAM refers solely to solid-state memory devices (either DRAM or SRAM), and more specifically the main memory in most computers.RAM is called "random access" because any storage location can be accessed directly. RAM is organized and controlled in a way that enables data to be stored and retrieved directly to specific locations. Types of Static Random-Access Memory: -Non-volatile SRAM, Asynchronous SRAM, Bipolar Junction Transistor, Metal Oxide Semiconductor Field Effect Transistor (MOSFET), Quad Data Rate SRAM, DDR SRAM, Binary SRAM and Ternary SRAM. Types of Dynamic Random-Access Memory: - SDRAM, DDR SDRAM, DDR2 SDRAM, DDR3 memory SDRAM, DRDRAM, PSRAM, RLDRAM, EDO DRAM, SGRAM and FPM DRAM. Most personal computers are designed to allow you to add additional RAM modules up to a certain limit. Having more RAM in your computer reduces the number of times that the computer processor has to read data in from your hard disk, an operation that takes much longer than reading data from RAM. This makes the computer works faster than ever.