Sola scriptura (Latin: by Scripture alone) is a Christian theological doctrine which holds that the Christian Scriptures are the sole infallible rule of faith and practice.
The Scriptures’ meaning is mediated through many kinds of secondary authority, such as the ordinary teaching offices of the Church, the ecumenical creeds, the councils of the Christian Church, and so on. However, sola scriptura rejects any original infallible authority other than the Bible. In this view, all secondary authority is derived from the authority of the Scriptures and is therefore subject to reform when compared to the teaching of the Bible. Church councils, preachers, Bible commentators, private revelation, or even a message allegedly from an angel or an apostle are not an original authority alongside the Bible in the sola scriptura approach.
Sola scriptura is a formal principle of many Protestant Christian denominations, and one of the five solas. It was a foundational doctrinal principle of the Protestant Reformation held by the Reformers, who taught that authentication of Scripture is governed by the discernible excellence of the text as well as the personal witness of the Holy Spirit to the heart of each man. Some Evangelical and Baptist denominations state the doctrine of sola scriptura more strongly: Scripture is self-authenticating, clear (perspicuous) to the rational reader, its own interpreter (“Scripture interprets Scripture”), and sufficient of itself to be the final authority of Christian doctrine.
By contrast, the Anglican Communion and the Methodist Church, though generally considered a form of Protestantism, uphold the doctrine of prima scriptura, with Sacred Scripture being illumined by tradition, reason, and in Methodism, experience as well. The Eastern Orthodox Church holds that to “accept the books of the canon is also to accept the ongoing Spirit-led authority of the church’s tradition, which recognizes, interprets, worships, and corrects itself by the witness of Holy Scripture.” The Catholic Church regards the Apostolic preaching and writing (a.k.a. Tradition and Scripture) as equal since both came from the Apostles. The Catholic Church describe this as “one common source … with two distinct modes of transmission,” while some Protestant authors call it “a dual source of revelation.”
(Main source: Wikipedia)