The are two major differences between RAM (random access memory) and ROM (read-only memory). The first is that RAM requires a power source to retain its information, whereas ROM can retain its information when its power source is removed. Secondly they differ in the tasks they are used for, with ROM used to store programs and files and stockpile the data needed to run them. Any data created, or needed, by them to perform their allotted task is held in RAM.

The most common type of programmable ROM chip in a computer is the BIOS (basic input/output system), which is responsible for testing and powering up any hardware. It will then locate the operating system, load it and give it control of the computer’s systems. RAM is generally in the form of a chip, while ROM is composed of magnetic tapes. RAM is also significantly larger and more expensive than the equivalent amount of ROM.

They Key Difference between RAM and ROM are discussed below:

RAM is Random Access Memory.
ROM is Read Only Memory.

RAM is the memory available for the operating system, programs and processes to use when the computer is running.
ROM is the memory that comes with your computer that is pre-written to hold the instructions for booting-up the computer.

RAM requires a flow of electricity to retain data (e.g. the computer powered on).
ROM will retain data without the flow of electricity (e.g. when computer is powered off).

RAM is a type of volatile memory. Data in RAM is not permanently written. When you power off your computer the data stored in RAM is deleted.
ROM is a type of non- volatile memory. Data in ROM is permanently written and is not erased when you power off your computer.