Computer memory is any physical device capable of storing information temporarily or permanently. For example, Random Access Memory (RAM), is a volatile memory that stores information on an integrated circuit used by the operating system, software, and hardware.And ROM(Read Only Memory) which is permanent memory.
Volatile vs. non-volatile memory
Memory can be either volatile and non-volatile memory. Volatile memory is a memory that loses its contents when the computer or hardware device loses power. Computer RAM is an example of a volatile memory and is why if your computer freezes or reboots when working on a program, you lose anything that hasn’t been saved. Non-volatile memory, sometimes abbreviated as NVRAM, is a memory that keeps its contents even if the power is lost. EPROM is an example of a non-volatile memory.
What happens to memory when the computer is turned off?
As mentioned above because memory (RAM) is a volatile memory when the computer loses power anything stored in RAM is lost. For example, as you are working on creating a document it is stored in RAM if it is not saved to a non-volatile memory (e.g., the hard drive) it would be lost if the computer lost power.
Memory is not disk storage
It is very common for new computer users to be confused by what parts in the computer are memory. Although both the hard drive and RAM are memory, it is more appropriate to refer to RAM as “memory” or “primary memory” and a hard drive as “storage” or “secondary storage.”
When someone asks how much memory is in your computer, it is often between 1 GB and 16 GB of Random Access Memory (RAM) and several hundred gigabytes of even a terabyte of hard disk drive storage. In other words, you always have more hard drive space than RAM.