The archaic period in Greek art takes a lot from the art of Egypt. The figures look stiff and unbending and are characterized by what is called the archaic smile. It is the earliest period of ancient Greek art, from around 750 B.C. until about 500 B.C.
The Classical Period followed the Archaic. Sculptures of the figure look more natural and easy, as artists mastered the rendition of the body and the ability to imply motion. The Classical period lasted until about 350 B.C.
The Hellenic period coincides with the reign of Alexander the Great. More detailed musculature is used, such as you see in the Belvedere Torso. More extreme curves and exaggerated movements are implied. The sculptural group "Laocoon and Sons," with the three figures being wrapped up by an enormous serpent, is a prime example.
Greek sculptures are admired for their clean beauty and for the austerity of the white marble they are made of, but the sculptures were originally painted. In addition, jewels or semi-precious stones were inserted in the eyes of many sculptures to provide sparkle. The paint on these sculptures has long been washed away, and the stones removed because of their value.
The most famous work of Greek architecture is the Parthenon, finished in about 430 B.C. Many similar buildings are found not just in Greece but in present-day Italy and Turkey.