What Is Computer Memory and How Does It Work

Short answer

Computer memory stores data and instructions that the CPU needs to access quickly. It comes in volatile forms like RAM and non-volatile forms like SSDs.

How it works

RAM uses electrical charges in capacitors to store bits. Because the charge leaks, RAM must be refreshed constantly, making it volatile. Each memory cell has a unique address that the CPU references.

Example

When you open a program, its instructions are copied from storage into RAM so the CPU can fetch them in nanoseconds rather than milliseconds.

Why it matters

Memory speed and size determine how many applications you can run simultaneously and how quickly they respond. Insufficient RAM causes swapping to disk, which is orders of magnitude slower.