Original: In botany and ecology a shrub is more specifically used to describe the particular physical structural or plant life-form of woody plants which are less than 8 m high and usually have many stems arising at or near the base.
Simplified: In botany and ecology a shrub is more specifically used to describe the particular physical structural or plant life-form of woody plants which are less than 8 meters high and usually have many stems arising at or near the base.