Democritus (ca. 460 BC-ca. 370 BC) was a Greece philosopher.
Very little is known about Democritus' life, but historians do know he was born in Abdera, Thrace (now part of modern Greece). His birth and death date are estimated.
As the pupil of Leucippus, he became interested in atoms. His belief was that all matter is made up of little units called atoms. Although he was persecuted at the time, this idea was picked up by scientists after him, and progressed into one of the greatest scientific discoveries.
According to Diogenes Laertius, Protagoras studied with Democritus.