Memory Characteristics and Functions

• Memory provides the CPU with a working storage area for program instruction and data.
• Random Access Memory(RAM) which is temporary memory. Computer performance is depend on the CPU and the capacity of RAM.
• Memory is located close to the CPU to decrease access time.
• A part of the main computer system
• The processor or the CPU directly stores and retrieves information from it.
• CPU access this memory randomly it means that the CPU to either read information from it or store information in it can access any location of this memory.
• Two types of memory technology implement the primary memory itself.
• Primary memory is much faster,
• VOLATILE in nature
• the capacity is small.

Storage Capacity

• Like the CPU, memory devices contain thousands of circuits imprinted on a silicon chip.
• Each of these circuits act as a switch (either on or off)
• Usually eight bit are used to represent a character, Eight bits form one byte.

Name	Abbreviation	Numbers of bytes
Byte	B	1
Kilobyte	KB	1024 Bytes
Megabyte	MB	1024 Kilobytes(about 1 million)
Gigabyte	GB	1024 Megabytes(about 1 billion)
Terabyte	TB	1024 Gigabytes(about 1 trillion)
Petabyte	PB	1024 Terabytes(about 1 quadrillion)

Types of Memory 

1. RAM: Random Access Memory is temporary and has a high speed access
2. ROM: Read Only Memory is fixed and contains a set of hard coded instructions.
3. Cache: A type of high speed memory that CPU uses to store instructions waiting to be processed. Temporary memory which is used by CPU to store instructions to be executed.

Today's Memory 

DDR SDRAM (double data rate synchronous dynamic random access memory)