Main memory refers to memory used for volatile memory - data is lost when power is off.
Primary memory is computer memory that a processor or computer accesses first or directly. It allows a processor to access running execution applications and services that are temporarily stored in a specific memory location.
We have Secondary Memory used for non-volatile memory.
There are two sub-categories within Primary Memory:
In practice, for computers, it’s mostly RAM, you don’t really need to think about ROM.
What about Flash Memory, does that count as main memory?
No, flash memory is not considered main memory. Flash memory is a type of non-volatile storage used for saving data persistently, so it is considered Secondary Memory.