Robin is the name of several characters in the DC Universe. There have been many incarnations of Batman's sidekick.
The first incarnation of Robin was Richard "Dick" Grayson. The youngest in a family of acrobats known as the "Flying Graysons", Dick watches a mafia boss kill his parents in order to extort money from the circus that employed them. Bruce Wayne/Batman takes him in as his legal ward, retconned in some cases as his adopted son, and eventually as his crime-fighting partner Robin. He is written out by many authors as the first son of Batman as well as his prodigal son. Throughout Dick's adolescence, Batman and Robin are inseparable. However, as Dick grows older and spends more time as the leader of the Teen Titans, he retires as Robin and takes on his own superhero identity, Nightwing, to assert his independence (others would fill in as Robin).
The second incarnation of Robin was Jason Todd. One night, Batman caught young Jason taking the wheels off the Batmobile. He took Jason Todd under his wing and trained him to become Robin. Throughout Jason Todd's career as Robin, Batman noticed violent nature inside of Jason. Then one night, while Batman and Jason are on a mission, Jason is kidnapped by the Joker. The Joker brutally cripples Jason with a crowbar and ultimately kills him with bomb. Batman hurries to the wreckage, only to find Jason's dead body. Later, Ra's al Ghul resurrects Jason by using his Lazarus Pit, a pool of chemicals that can raise the dead. Jason returns to Gotham under the alias of Red Hood, becoming the second person to take the name, with the first being the Joker. He returns to seek revenge on both the Joker and Batman: Batman for not killing the Joker long ago and the Joker for being Jason's murderer in the first place.
The third incarnation of Robin was Timothy Jackson "Tim" Drake. Tim Drake is the son of Jack and Janet Drake, coming from the same social class as Bruce Wayne. When he was a young child, he visited the circus for the first time with his parents. The Drakes asked the Flying Graysons for a photo together, resulting in a momentary bond between Dick Grayson and Tim Drake as they met for the first time.
After reaching the age of nine, Drake deduces the identities of Batman and Robin as Bruce Wayne and Dick Grayson after witnessing a gymnastic move by Robin that Grayson displayed while performing with the Flying Graysons. Noting that Batman has grown reckless and violent following the death of second Robin, Jason Todd, who was murdered by the Joker, Drake decided to intervene and Batman eventually enlisted him as the third Robin after the death of his mother and the crippling of his father.
When Jean Loring sent him a gun he used it in self-defense and killed Captain Boomerang, but at the last second, Captain Boomerang threw a boomerang that killed Jack Drake. As a result Tim became an orphan, continuing the long held tradition that Robin is an orphan. After Batman's apparent death in Batman R.I.P. and Final Crisis, Bruce Wayne's biological son Damian Wayne takes up the Robin identity while Tim Drake, believing that his mentor is still alive, assumes the identity of Red Robin and leaves Gotham City to go on a worldwide search for Bruce Wayne.
The fourth incarnation of Robin was Stephanie Brown. Stephanie Brown is the daughter of the Cluemaster, one of Gotham City's third-rate criminals. Her father spent most of her childhood in jail or away from the family. He claims to be rehabilitated upon his return to Gotham, but Stephanie becomes furious when she discovers that he is actually returning to crime, this time not leaving his trademark clues behind. She decides something needs to be done. Stephanie tailors a costume for herself, and calls herself The Spoiler due to her attempts to "spoil" her father's plans. She learns where her father is hiding out, finds out his plans, and leaves clues so that the police and Batman could stop him. Robin (Tim Drake) tracks her down and, after a few brief confrontations, helps capture Cluemaster. Although she initially wishes to kill her father, Batman convinces her to allow him to be arrested.
Stephanie snaps Tim out of his depression just as his father discovers he is Robin. After Warlock's death, Tim's father orders him to hang up his cape, and Tim is forced to live a normal life for a time. One day after school, Stephanie attempts to surprise Tim with a visit. As she arrives, however, she catches a female classmate, Darla Aquista, attempting to seduce him. Assuming yet again that Tim is being unfaithful, she breaks off ties with Tim and angrily decides to put her attention elsewhere.
Creating a homemade Robin costume, Stephanie sneaks into the Batcave and demands that Batman train her as the new Robin. Batman reluctantly accepts her as the new Robin, puts her through several months of intensive training, and makes her a better costume with roughly the same design as Tim's. As Robin, she patrols with Batman, but he thinks she is too unskilled to be an acceptable replacement for Tim. Batman later fires her after she disobeys his orders during two missions.
The fifth incarnation of Robin was Damian Wayne al Ghul. Damian Wayne al Ghul is the son of Bruce Wayne and Talia al Ghul. Damian's origin is unknown to Batman. Genetically perfected and grown in an artificial womb, Damian was intended to be a formidable warrior. He is raised by Talia and the League of Assassins. He becomes a talented martial artist by the time he is a pre-teen, at which time Talia reveals Damian's existence to Bruce Wayne and leaves him in Batman's custody in an effort to disrupt Batman's work.
Precocious, spoiled, and violent, Damian battles Tim Drake, whom he wants to replace as Robin, and sucker punches Drake off the stuffed Tyrannosaurus in the Batcave when Tim stops fighting to help him. Damian then escapes, dons a variant Robin costume made of Jason Todd's old tunic and mask and assorted League of Assassin gear, and gets into a fight with and decapitates the villainous Spook. Although misguided and malicious, Damian seems to genuinely want to aid Wayne's war on crime as he sees himself as Wayne's son and wants Wayne's approval. Unfortunately, because of how he was raised, Damian lacks any sort of common sense in regards to social behavior, and believes that in order to be accepted by Batman, he must kill any rivals, which included Tim Drake. Eventually, Batman confronts Talia to confirm Damian's true identity, but both Talia and Damian are soon caught in an explosion. They survive the explosion. But Damian's badly injured body requires transplants of harvested organs, which his mother orders her physicians to carry out. Damian makes a full recovery.
After the events of Batman R.I.P. and Batman: Battle for the Cowl, Damian takes up the identity of Robin at ten years of age, becoming the fifth person to use the Robin identity.
The sixth incarnation of Robin was Helena Wayne. Helena Wayne is the daughter of Batman and Catwoman of Earth-Two. Helena was born in 1957 to Bruce Wayne and Selina Kyle Wayne, and grew up enjoying the benefits of being in a wealthy household. As a youth, she enjoyed a thorough education, as well as being trained by her parents, Batman and Catwoman, to become a superb athlete. As a young girl she was amazed to learn that her father was Batman and embraced Dick Grayson/Robin as her older brother. She also looked up to Alfred as a second father. After finishing school, she joined the law firm of Cranston and Grayson, one of whose partners was Dick Grayson, alias Robin.