Colonization (or colonisation) occurs whenever any one or more species populate an area. The term, which is derived from the Latin colere, "to inhabit, cultivate, frequent, practice, tend, guard, respect", originally referred to humans. During the 19th century, biogeographers appropriated the term to also describe the activities of birds, bacteria, or plant species. Human colonization is a narrower category than the related concept of colonialism. Colonization refers strictly to migration, for example, to settler colonies, trading posts, and plantations, while colonialism deals with this as well as the ruling of new territories' existing peoples.