In Greek mythology, is Ares and Mars the same person?

Ares is the Greek counterpart for Mars. Ares is the god of war, more so that of slaughter. Mars is the Roman war god, who originally was worshipped as a god of spring and fertility. When the Empire expanded he came to be more closely identified with Ares. However, because of his role in the foundations of Rome (being the legendary father of Romulus and Remus) the Romans identified themselves as a martial people, and his worship was second only to Jupiter. So in that respect Mars was held in muhc higher esteem that that of Ares with the Greeks.