Microgreens are young plants that have been grown to the point of producing their cotyledons - or perhaps a bit further.

There are also Minigreens - which green plants grown in a confined space to the point where they are producing their first few pairs of true leaves.

Minigreens can be grown "sustainably" - harvesting leaves from the plants a few at a time, without killing the individual plants. This reduces production costs, and makes Minigreens convenient to produce. However, their nutritional properties are usually not quite as attractive as genuine Microgreens.