A bud is a condensed shoot in which the stem is very short, the inner leaves are closely packed and the outer scale leaves form a protective covering. In the spring, the stem elongates rapidly and the leaves unfold.

A bud at the tip of a twig is a terminal bud and contains the growing point; lateral buds develop in leaf axils along a twig.

The term bud is also used in zoology for a point from which new growth develops.