Memory

Random Access Memory (RAM)

• Known as the computer’s ‘short-term memory’ where data is temporarily stored.
• Data in the RAM is volatile, which means it disappears when the computer is turned off.
• If a computer doesn’t have enough RAM, it might run slowly when multiple programs are open.
• The RAM holds the data and instructions that the CPU needs, providing the CPU with information faster than getting it from the hard drive.

Read Only Memory (ROM)

• The ROM is the computer’s ‘long-term memory’ where essential system software is stored.
• Unlike RAM, this memory is non-volatile, meaning the data stored in this memory is retained even when the computer is turned off.
• A typical use of ROM is to store the Bootstrap program, which loads the operating system into RAM when the computer starts up.

Virtual Memory

• When RAM is full, the operating system uses space on the hard drive for temporary storage, which is called virtual memory.
• It moves data from RAM to a space called a paging file to free up RAM.
• However, since hard drives are slower than RAM, this makes the computer operate slower.

Cache Memory

• This is a small amount of high-speed volatile memory available to the CPU, faster than RAM.
• It is used to temporarily store frequently accessed data by the CPU to speed up processing.
• If the CPU finds data it needs in the cache, it is called a cache hit. If it doesn’t, it’s a cache miss, and the CPU must retrieve the data from RAM or other memory. This is slower and decreases performance.