what is the definition of ram and also define types of ram

what is the definition of ram and also define types of ram

RAM definition

1. RAM is an acronym for random access memory, a type of computer memory that can be accessed randomly; that is, any byte of memory can be accessed without touching the preceding bytes. RAM is the most common type of memory found in computers and other devices, such as printers.

2.  The main memory in a computer, smartphone or tablet. RAM is the temporary work space where instructions are executed and data are processed. What makes RAM "random access" is its capability of reading and writing any single byte. This "byte address ability" differs from storage devices such as hard disks and flash memory chips, which read and write sectors containing multiple bytes. 

3. Random-access memory (RAM) is a type of storage for computer systems that makes it possible to access data very quickly in random order. The term RAM has become associated with the main memory of a computer system.

4. RAM (random access memory) is the place in a computer, tablet, mobile where the operating system, application programs, and data in current use are kept so that they can be quickly reached by the computer's processor. RAM is much faster to read from and write.  However, the data in RAM stays there only as long as your computer is running. When you turn the computer off, RAM loses its data. When you turn your computer on again, your operating system and other files are once again loaded into RAM, usually from your hard disk.

RAM types mostly used in computing devices.

Because of power, price, storage and functionality, RAM can be divided into two basic types.
1.  DRAM (Dynamic Random Access Memory)
2.  SRAM (Static Random Access Memory)

1.  SRAM

This is a type of memory chip which is faster and requires less power than dynamic memory.  Static random access memory (SRAM) that requires 6 transistors. In terms of speed, SRAM is faster.  DRAM needs to be refreshed thousands of times per second while SRAM does not need to be refreshed, which is what makes it faster than DRAM.  Like DRAM it retains data bits in its memory as long as power is being supplied.  SRAM can give access times as low as 10 nanoseconds.

1.  DRAM

It is mostly used in computing devices (primarily PCs).  The most common type of RAM is dynamic RAM (DRAM).  This type of random-access memory stores each bit of data in a separate capacitor within an integrated circuit. This captivator needs to be refreshed often otherwise information fades. DRAM has one capacitor and one transistor per bit   The capacitors and transistors that are used are exceptionally small. There are millions of capacitors and transistors that fit on one single memory chip. DRAM supports access times of about 60 nanoseconds.

Types of SRAM

SRAM can be divided into three main types.
1.  Level 1 cache (L1)
2.  Level 2 cache (L2)
3.  Level 3 cache (L3)

Types of DRAM

Because of wider usage and changing in technology day by day DRAM can be into different types describe below.

1.  FPM (fast page mode DRAM). Introduced in 1987.  An early form of DRAM. This computer memory type was frequently mounted on a SIMM in 486 and early Pentium computers.

2.  EDO (extended data output). EDO offers a slight performance boost over FPM.  Introduced in 1995, EDO requires a specific chip set and is limited to bus speeds of 66 MHz. These chips are mounted on SIMM modules.

3.  BEDO (burst EDO RAM). This is a faster version of the EDO RAM chip in which read and write operations send bursts of data in batches of four.

4.  SDRAM (synchronous DRAM). SDRAM synchronizes itself with the microprocessor clock speed allowing faster access to memory. These chips are mounted on DIMM memory modules and are classified according to the CPU speed they are designed to support.

5.  ESDRAM (enhanced SDRAM). This version of SDRAM includes a small SRAM cache in order to reduce latency and speed up operations.

6.  SLDRAM (synchronous link dynamic RAM). This is an advance prototype version of SDRAM, which was designed as a royalty-free.  An open-industry standard design alternative to RDRAM.

7.  DDR (double data rate SDRAM). DDR allows data transfers on both the rising and falling edges of the clock cycle, which doubles the data throughput. DDR SDRAM chips are mounted on 184-pin DIMM modules and are typically available in 128 Mb to 1 GB capacity. They operate at different bus speeds like 266, 333, 400 MHz.

8.  DDR2. These chips are the next generation of DDR SDRAM memory. They are mounted on 240-pin DIMM modules, can operate at higher bus speeds and have a capacity to hold 256 Mb to 2 GB of memory. DDR2 has twice the latency of DDR but delivers data at twice the speed of DDR.

9.  RDRAM (Rambus DRAM). A proprietary protocol-based, high-speed memory technology developed by Rambus Inc., RDRAM has current frequencies of 800 MHz to 1200 MHz, and planned chip sets can expect to reach 1600 MHz. RDRAM RIMMs can only be used on motherboards or systems specifically designed for them.

10.  DDR3 RAM

The main notable improvements that DDR4 makes over its predecessor, DDR3, are a greater range of available clock speeds and timings, lower power consumption, and reduced latency. With DDR3, the options for your clock speed (i.e., how fast the RAM can read or write data) are primarily geared to one of four different choices: 1333Mhz, 1600Mhz, 1866Mhz, and 2133Mhz, with 2133Mhz being the maximum limit. 800Mhz and 1066Mhz configurations do technically still exist, but for the most part these have been phased out of production in favor of their faster cousins.

11.  DDR4 RAM

DDR4 SDRAM is the abbreviation for "double data rate fourth generation synchronous dynamic random-access memory", the latest variant of memory in computing. DDR4 is able to achieve higher speed and efficiency thanks to increased transfer rates and decreased voltage.  Samsung manufactured the first DDR4 memory console in 2011. 

First off, DDR4 operates at a lower voltage than DDR3. DDR4 runs at 1.2 volts, down from 1.5. It doesn't sound like much, and it's really not for your typical home PC. Most Haswell-E desktop systems (where you'll most often see DDR4 in use) will operate somewhere in the 300W to 1200W range. The voltage difference for those numbers might account for a 15W savings over DDR3—not a lot for a home user. But for server farms and other large-scale computer architectures, where you could have hundreds of systems running thousands of DDR4 modules, that 15W difference adds up. Another big difference between DDR3 and DDR4 is speed. DDR3 specifications started at 800 MT/s (or Millions of Transfers per second) and some went as high as 2133. DDR4, meanwhile, starts at 2133 MHz. The increased speed means an overall increase in bandwidth.