Robin is the faithful sidekick of The Batman, making his first appearance in Detective Comics #38. It was multi-billionaire Bruce Wayne's ward, Dick Grayson who would become "the boy wonder" after he, like Wayne, had witnessed his parents killed before his eyes
The eight-year old Grayson was the youngest member of the acrobatic circus act, "The Flying Graysons". After a gangster, Boss Zucco, sabotaged the their trapeze equipment resulting in the death of Grayson's parents, Bruce Wayne took custody of the boy as his legal ward (later adopting him as his son). Wayne trained the boy in the same ways that he had been trained during his time away from Gotham and the young Grayson became Robin, Batman's sidekick.
As he grew older, Robin gradually moved away from his status as the "boy wonder" changing the title to "teen wonder" before, eventually, leaving the mantle of Robin completely to become the hero, Nightwing.
Jason Todd made his initial appearance in Batman #357 in 1983 as a red headed young acrobat who, like Grayson, had seen his parents killed, here, by Killer Croc. This would later be revised after the "Crisis On Infinite Earths" saga. Now, Todd was a black haired street orphan whose first encounter with The Batman came while he made an attempt at stealing one of the Batmobile's tires.
After Grayson left to become Nightwing, Todd helped The Batman to catch a gang of theives thus proving to The Dark Knight his abilities as a crime fighter. Batman made the decision that Todd would become the new Robin.
Batman's relationship with the new Robin, although initially fine, soon took a turn for the worse and the two were constantly arguing. The situation came to a head when Todd left Gotham to search for his biological mother in Ethiopia. Although Batman follows the boy, Todd eventually finds his mother working for - and being blackmailed by - The Joker. In a insanity-driven burst of rage, The Joker beat Robin within an inch of his life before leaving both he - in a pool of his own blood - and his mother in a warehouse with a time bomb. Batman raced to save his young partner but was too late. The warehouse exploded killing both Robin and his mother. To this day, Batman keeps Jason's costume in a glass container in the batcave in memory of the boy.
Tim Drake first appeared in Batman #436 in 1989 in a flaskback that showed him as a young boy eagerly following the adventures of Batman and Robin. Using his amatuer detective skills, Drake managed to decipher the true identities of Batman and Robin. Seeing the boys potential, Bruce Wayne made the decision to make Drake the new Robin. Although his combat skills were no match for Grayson's, Drake's detective skills make him a worthy sidekick for The Dark Knight who feels that the boy will one day surpass even he, "The Worlds Greatest Detective", as a detective.
Parting from the original costume of a red tunic and yellow cape, the new Robin costume was somewhat more grown-up. The red tunic still remained in some capacity, but the flesh coloured tights would be replaced by green ones and the green shoes by tall, black boots, The cape, also, changed from a short, yellow piece to a long black cloak.
Upon Tim's resignation, his girlfriend, Stephanie Brown aka Spoiler, took the mantle of Robin. However, Drake would return to Batman's side after his short-lived replacement was killed at the hands of Black Mask.