In the United Kingdom, ancient woodland is that which has existed continuously since 1600 in England, Wales and Northern Ireland. Planting of woodland was uncommon before those dates, so a wood present in 1600 is likely to have developed naturally.

A woodland is, in the broad sense, land covered with woody plants, or in a narrow sense, synonymous with wood, a low-density forest forming open habitats with plenty of sunlight and limited shade. Some savannas may also be woodlands, such as savanna woodland, where trees and shrubs form a light canopy.