what are immediate, extended, and delayed releases?
(immediate release, extended release, delayed release)

Source: Food and Drug Administration (FDA)

What are the differences between an immediate release tablet/capsule, an extended release tablet/capsule, and a delayed release tablet/capsule?

Immediate-release tablets and capsules release the active ingredient within a small period of time, typically less than 30 minutes.

Extended-release tablets and capsules release the active ingredient at a sustained and controlled release rate over a period of time. Typically extended-release tablets and capsules release their ingredient with time periods of 8 hours, 12 hours, 16 hours, and 24 hours.

Delayed-release tablets and capsules release the pharmaceutical dosage after a set time. The delayed-release tablets and capsules are frequently enteric-coated in order to prevent release in the stomach and, thus, release the dosage in the intestinal track.

It is worth noting that sustained release, controlled release, and extended release have pretty much the same meaning and are used interchangeably.