ALTER EGO: DICK GRAYSON
Weapons of Choice: Motorcycle, batarangs, batropes, utility belt
As a young boy, Dick lived and worked with his parents as the circus act The Flying Graysons. Like Bruce Wayne his childhood was also shattered by the death of his parents at the hand of a small time crime lord. Dick was taken in as a ward of Bruce Wayne's. Dick discovered Bruce's secret life as Batman. Batman eventually allowed him to assist him in his crime fighting efforts and Robin was born.
Dick and Bruce later had a falling out when they developed differing opinions about their crime fighting techniques. This led Dick to give up the persona of Robin. For more information about Dick Grayson, see Nightwing.
ALTER EGO: TIM DRAKE
After Dick Grayson gave up his role as Robin, Batman worked alone for a while. After some time, he met up with Tim Drake. At our house, we like to refer to Tim Drake as "The Little Robin". My limited understanding is that Tim Drake's mother died when he was young. His father was a small time hood who got into trouble with a crime boss and skipped town. The mob then came after Tim to try to find out his father's whereabouts. Tim was taken in by Bruce Wayne and discovered his secret identity. He wanted to assist Batman in his crime fighting efforts but Batman refused. Tim eventually won him over and Batman allowed him to take over the job of Robin.