A shrub or bush is a category of plants. A tree usually has one stem, which at some height has branches. A shrub can have multiple stems from the bottom up. Usually, bushes do not grow as tall as trees, very often they are less than 1–2 m tall.
Very many plants can be either shrubs or trees, depending on the growing conditions. Small, low shrubs such as lavender, periwinkle and thyme are often termed subshrubs. Shrubs can be either deciduous or evergreen.
A shrubbery is a garden with shrubs as the main feature.