Quasimodo was an orphan, taken up by the church, primarily Frollo. Frollo was actually the one who saved him from his harsh life in the streets, and later Frollo used him as a Ringer Of The Bells in The Notre Dame De Paris.
Quasimodo is rather unpleasant to look at, due to his deformated body. This is the main reason he is not accepted in society.
In the novel, Quasimodo is treated badly by society for the entire book. He shows the respect of a dog to Frollo, even though he disobeys his orders several times and even kills him, when Esmeralda is hanged. He shows great love and care for Esmeralda.
Quasimodo appears much more cheerful and happy in the animated film. He still loves Esmeralda and is still heartbroken by the fact the she's in love with Phoebus, but not neraly as much as in the novel. In the end of the animated version, he is accepted into society completely.