Internal Memory

Internal Memory is the memory device that often use by Central Processing Unit (CPU) for the fast performance.However,the faster the performance the higher the cost of memory per bit.

• Internal Memory is volatile except the ROM.
• Cost per bit compare to external Memory is more expensive.
• Function of Internal memory is to Temporarily store data and instructions that are being executed or will be executed by the CPU.

Internal Memory can divided into 3 types:

1. Register
2. Cache
3. Main Memory

Register 

• located inside the processor.
• Each register typically holds a word of data (often 32 or 64 bits).
• Fastest of all forms of computer data storage but also most expensive.

Cache

• Processor cache is an intermediate stage between ultra-fast registers and much slower main memory.
• It's introduced solely to increase performance of the computer.
• Most actively used information in the main memory is just duplicated in the cache memory, which is faster, but of much lesser capacity.
• Slower but storage size is larger than registers. 

Main Memory

• Primary Memory of a computer
• Speed slower than cache but storage size is much bigger than cache 
• Low cost than cache and Register
• Types of main memory 
• Random Access memory(RAM)
• Read Only Memory(ROM)