Homo habilis is the earliest known species of the genus Homo; that is, the first human species. It existed from approximately 2.2 to 1.6 million years ago in east Africa.

Homo habilis brains are about 30% larger than those of A. africanus. Some stone tools , such as crude hand axes and stone flakes have been found. They could have been manufactured as needed or as opportunity arose. Homo habilis was first discovered in 1959 in the Olduvai Gorge in Tanzania.

Homo erectus is a large brained species. The tools of Homo erectus are the first in the fossil record to show conscious design of any complexity. Homo erectus may have been the first species to use and control fire. Control of fire may have enabled humans to move out of Africa and into colder climates in Europe and Asia. Tools and remains of this species have been found widely distributed in Europe and Asia.

Homo sapiens is the earliest forms of our own species. The surviving physical evidence suggests that the transition from Homo erectus to Homo sapiens occurred approximately 300,000 to 400,000 years ago.

Homo sapiens neanderthalensis
or 'Neanderthal Man' was a robust human species occupying Europe and western Asia. The Neanderthal were the first humans to live in Ice Age conditions, surviving by hunting the largest and most formidable mammals - the mammoth, the rhinoceros, and wild cattle. Scientists still debate whether they are a related sub-species of modern humans or represent a side line of the late Homo erectus, related to but not ancestral to modern humans.

www link :
Text about Human Prehistory
form the University of Washington.