What major impact did protestant have on the catholic church?

Protestantism and Catholicism are two different sects of Christianity, and there are many more. Protestants protested against the Catholic Church, hence the name. One major issue with the Catholic Church was the selling of indulgences, sheets of paper used for forgiveness. With this method, the church would make money. This was a critical issue society had with the church, and the Protestants decided to go against this.