Computer Memory

In order to run code, computers need to keep track of pieces of information like variables.

computer memory diagram

The three main forms of memory are cache, main memory and secondary memory.

Cache: Holds temporary data that is frequently used by the CPU.
Extremely fast

Limited capacity and very expensive
Main Memory: Holds the current programs, instructions and data.
A computer's main memory is RAM

Faster than secondary memory, but slower than cache

Volatile memory (requires power to retain stored data)
Secondary Memory: Holds data or information that is permanent.
Can be a hard drive, disk drive, USB, etc.

Slower than main memory

No volatile (does not require power to store memory)

Stack vs Heap

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