Depending on the age of your Mac, it may contain a small amount of special memory called Non-Volatile RAM (NVRAM) or Parameter RAM (PRAM). Both store settings that your Mac uses to manage the configuration of various systems and devices.

The difference between NVRAM and PRAM is mostly superficial. Older PRAM used a small, dedicated battery to keep power to the RAM at all times, even when your Mac was unplugged. Newer NVRAM uses a type of RAM similar to the flash-based storage used in SSDs to store the parameter information without the need for a battery to keep it safe.

Aside from the type of RAM used and the name change, both devices serve the same function: they store important information that your Mac needs when it boots up or accesses various services.

Most Mac users don't think much about their Mac's RAM parameter, but it works hard anyway, keeping track of the following things: