The Reformation was a 16th and 17th century movement challenging the Catholic Church in Europe. Led by Martin Luther, it sparked the rise of Protestantism and led to religious conflicts across Europe.
Luther and the Protestant Reformation - Crash Course World History
The Counter-Reformation, or Catholic Reformation as it is also known, stemmed from The Council of Trent (held from 1545 to 1563). It was largely a response to the Protestant Reformation and the series of meetings concentrated on establishing order and defining/reaffirming Catholic teachings, as well as eliminating corruption within the Church.
The Counter-Reformation (Part 4 in The Reformation series from SmartHistory).