A savanna or savannah is a mixed woodland-grassland ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of grasses. According to Britannica, there exists four savanna forms; savanna woodland where trees and shrubs form a light canopy, tree savanna with scattered trees and shrubs, shrub savanna with distributed shrubs, and grass savanna where trees and shrubs are mostly nonexistent.
A tree savanna in Tanzania, East Africa (Tarangire National Park)
A grass savannah in South Africa (Kruger National Park)
A savanna woodland in Northern Australia demonstrating the regular tree spacing characteristic of some savannas.
Bushfire in Kakadu National Park, Australia
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.
An open woodland in North Lanarkshire, Scotland
Miombo woodland in Malawi
A dry sclerophyll woodland in western Sydney.
An open woodland in Northern Illinois supporting an herbaceous understory of forbs and grasses