Ordinary Magisterium: Pope and Bishops regularly preach the Good News in homilies and in their regular letters to their dioceses. Most often, these are to encourage faith and devotion, clarify a point of faith or to give instructions. The most well-known are those written by the Pope. An example of this is Evangelium Vitae by Pope St John Paul II which clarified the Churches on modern ethical issues that affect the sanctity of life.
Extraordinary Magisterium: Sometimes the Church needs to respond to specific disputes or particular circumstances. These have more importance than the ordinary teaching role of the Pope and the bishops, so they are called the extraordinary magisterium.
Conciliar Magisterium: Sometimes the bishops of the Church are asked to sit in the General council. The task of a General council is to explore matters of significance to the life of the Church. This could be a specific doctrine or guiding the Church's response to developments in the modern world.
Pontifical Magisterium: Another form of extraordinary magisterium concerns specific and rare declarations by the pope. The Pope has the authority to make the final decision on some disputed matters of faith or morals. These rules are also known as the ex cathedra declarations.