Martin Luther nailed 95 theses to a church door, mainly as an attack against the sale of 'indulgences". What are "indulgences" and are they still offered today?

The medieval indulgence was a writ offered by the Church, for money, guaranteeing the remission of sin, and its abuse was the spark that inspired Martin Luther's 95 Theses.

Both partial and plenary indulgences can be granted by the diocesan bishop or eparch, by the major archbishop, metropolitan and patriarch, by the cardinal, as well as by the Pope and the Apostolic Penitentiary.

The Catholic Church does not now nor has it ever approved the sale of indulgences.