Helios also known as Helius or Sol is a titan. Since Helios is a titan, a member of the earlier order gods and goddesses which preceded the  later  Olympians. Whenever you encounter the "os" ending in a name it usually indicates an earlier pre-Greek origin. Helios has two sisters named Eos and Selene with no brothers. Eos meaning dawn and Selene meaning moon. together they were the sun god, Dawn goddesses and the moon goddesses .Their mothers name was Theia and their fathers name was Hyperion. Most often, people viewed or portrayed helios as a mighty charioterr, driving his flaming chariot with his horses from east to west across the sky every day.  Some more fun facts include:

• Helios was worshipped in various places of the Peloponnesos, but especially on Rhodes, where each year gymnastic games were held in his honor.
  
• Helios was depicted as a handsome, and usually beardless, man clothed in purple robes and crowned with the shining aureole of the sun. His sun-chariot was drawn by four steeds, sometimes winged. Helios was identified with several gods including fiery Hephaistos and light-bringing Apollon. 
• Helios' Weaknesses: His intense fire can burn
•  In later times he was identified with Apollo. Apollo being the god of light. 
•   There the famous Colossus represented him, and an important festival was celebrated in his honorIt is interesting to note that the Dawn goddess Eos began the procession of morning, followed closely by her brother Helios.