"Woodland" is often just another name for a forest. Most of the time, though, geographers use the term to describe a forest with an open canopy. The canopy is the highest layer of foliage in a forest. It is made up of the crowns, or tops, of trees. An open canopy allows full sunlight to enter the woodland, limiting shade and moisture.

Woodlands are often transition zones between different ecosystems, such as grasslands, true forests, and deserts.

Woodlands that lead to grasslands are sparse. Grasslands, sometimes called prairies or savannas, are composed mostly of grasses and have few trees. The woodlands of Ethiopia border grasslands in the highlands of the Horn of Africa. Ethiopian woodlands are densely populated and contain some of the best agricultural land in the country. Organisms that live in the Ethiopian woodlands must be able to thrive in both the partly shady woodland and the open grassland. The critically endangered Walia ibex (Capra walie), a type of small mountain goat, is such an animal.

Woodlands can also transition to true forests, which are larger and have denser foliage and closed canopies. Eucalyptus forests, composed of the most common type of tree in Australia, are often surrounded by eucalyptus woodlands. The trees themselves are often the same, but woodland eucalyptus trees have fewer branches and are shorter than forest varieties.

Woodlands that border desert ecosystems are sometimes called xeric woodlands. (Xeric means dry.) The succulent woodlands on the island of Madagascar, located off the southeast coast of Africa, are xeric woodlands. Succulent woodlands are full of cactus-like plants that are adapted to hot, dry climates.