Catholics refer to something called Tradition. What is it? Where does it come from? And why would anyone care about anything except the Bible, anyway?

Well, Sacred Tradition comes from Christ. It's the full, living gift of Christ to the Apostles, faithfully handed down through each generation. It is through Tradition that the Holy Spirit makes the Risen Jesus present among us, offering us the very same saving Word and Sacraments that He gave to the Apostles. Understanding Catholic Tradition is essential to understanding the Catholic Church and the Catholic Christian faith.

The word "tradition" actually means handing down something to another person. God’s Word, the Bible, testifies to this meaning of Catholic Tradition as the normal mode of transmitting the Faith: "So then, brethren, stand firm and hold to the traditions which you were taught by us, either by word of mouth or by letter." (2 Thessalonians 2:15), "For I received from the Lord what I also handed on to you..." (1 Corinthians 11:23), "For I handed on to you as of first importance what I also received..." (1 Corinthians 15:3). See also 2 Timothy 1:11-14, 2 Timothy 2:1-2, and Jude 1:3.

This is the most basic meaning of Catholic Tradition: it is the true Faith itself, given to the Apostles by Christ and faithfully transmitted to each new generation. (Catechism of the Catholic Church, 77-78). Catholics often write Tradition, with a capital 'T', to mean Sacred Tradition. This Catholic Tradition is different from those traditions (small 't') that are merely customs, and which are not part of Divine Revelation.