Goliath the Gittite was a six cubit and a span, giant soldier in the Philistine army that challenged the Israelite army under King Saul to send a warrior to challenge him in a battle. As a Gittite, Goliath was from the city of Gath, one of the five city-states of the nation of Philistia. Goliath was a Rephaite, a member of a race of giants who all descended from Rapha. He had one brother named Lahmi who also was in the army and from Gath, as well as having several possibly near relatives.
Goliath had been a warrior from his youth.
During one battle against the Israelites, the Philistines encamped on a hill across the valley from them. Soon Goliath, a Champion in the Philistine army came out from the Philistine camp. Wearing a bronze helmet, a five-thousand shekel (approx 125 pounds or 58 kilograms) and bronze shinguards. Slung on his back was a javelin, whose tip weighed six hundred shekels (approx 15 pounds or 6.9 kilograms). Ahead of him went a shield bearer.
This went on for 40 days until young David arrived, bringing food for his three older brothers in the ranks.
When David heard Goliath's challenge, he accepted, proclaiming his faith in the God of Israel. Armed with only a slings and five stones, he met Goliath at the battlefield between the two armies, killing him with a single stone to the giant's forehead. After Goliath fell to the ground dead, David used Goliath's sword to cut off his head.
The Philistine army was routed by the Israelites after this, and this event began the career of David, who later became Israel's most famous King. Goliath's height was listed at six cubits and a span. If a cubit is about 18 inches as some think, Goliath would have been over nine feet tall.
There are four more giants killed by the Israelites in battle, that were all from the tribe of giants in Gath.It may be that the five stones David picked up to kill Goliath were used by David and his men to kill the other four Rephaite giants.