Primary memory and secondary memory are two types of computer memory, and the main differences between them are as follows:
| Primary Memory | Secondary Memory | |
|---|---|---|
| Location | Located on the motherboard | External to the motherboard |
| Access | Directly accessible by the CPU | Not directly accessible by the CPU |
| Speed | Faster than secondary memory | Slower than primary memory |
| Capacity | Smaller capacity | Larger capacity |
| Volatility | Volatile (loses data on power loss) | Non-volatile (retains data even after power loss) |
Primary memory, also known as main memory, is the memory that the CPU uses to store and access data and instructions during program execution. It is located on the motherboard and consists of two types of memory: RAM (Random Access Memory) and cache memory. RAM is volatile, which means that its contents are lost when power is turned off or lost, while cache memory is faster but smaller than RAM.
Secondary memory, also known as auxiliary memory, is the memory that the computer uses to store data and programs for long-term use. It is external to the motherboard and can be accessed via input/output (I/O) channels. Examples of secondary memory include hard disk drives, solid-state drives, USB flash drives, CD/DVD drives, and magnetic tape drives. Secondary memory is non-volatile, which means that its contents are retained even when power is turned off or lost, and it has a larger capacity than primary memory. However, it is slower than primary memory and cannot be directly accessed by the CPU.