RAM | Random Access Memory
RAM (Random Access Memory)
One of the important abilities of a computer is its ability to remember. Computer has internal (RAM or primary) storage as well as external (secondary) storage.
Memory unit that communicates directly with CPU is called main memory as shown below:
RAM is also known as primary memory or main memory. Whatever we see on the screen is stored in main memory (RAM). Also note that programs and data currently needed by the CPU will reside in main memory.
Primary memory can hold information only while computer system in ON. When computer is OFF, primary memory is erased. This feature of memory is called volatile. Note that primary memory has limited capacity, because it is expensive.
Units of Main Memory
Note that memories are organized into 8-bit multiples called bytes. Computer memory is usually expressed as multiples of bytes. Typical units of computer memory are as follows:
Bit = Binary digit (1 or 0) Byte = Group of 8 bits 1KB = Kilo byte = 210 Bytes 1MB = Mega byte = 220 Bytes 1GB = Giga byte = 230 Bytes 1TB = Tera byte = 240 Bytes
Note: Bit is the smallest unit of data that can be stored in memory.
