PRAM, or parameter random access memory, is a special type of battery powered RAM for older Mac computers.

Modern Mac computers don't use PRAM. Instead, they use NVRAM, or non-volatile random access memory.

But PRAM and NVRAM serve the same function. They both store some important information about your system like the startup disk, timezone, and so on.

If you're having some issues with your Mac computer, you may want to reset the PRAM / NVRAM. Here's how to do that:

  1. Shut down your Mac computer
  2. Turn on the computer, and immediately hold down these keys: Option + Command + P + R
  3. Hold down the keys until you hear the startup sound after about 20 seconds

Here's a video that goes over how to reset the PRAM / NVRAM and SMC (system management controller):