> Catholicism is a branch of Christianity. Used to be the only one until the Protestant Reform.

Er...no. The original split was between Catholicism and the Eastern Orthodox church. Protestants then split from Catholics later on.

Catholics don't pray to saints - they only pray to God. They do, however, believe in the power of intercessions and that's what they ask of the saints (e.g. St ..., pray for us; Mother Mary, pray for us).

It seems worth mentioning that a big part of the Protestant Reformation was the removal of the Deuterocanonical books. As a result, Catholics consider these books part of the Old Testament but Protestant Christians (the type of Christian I think most people mean when they are considering Catholics as distinct from Christians) do not. Source: https://en.wikipedia.org/wiki/Deuterocanonical_books