Presbyterianism is the name of a Protestant Christian tradition — a family of churches, not one single building with one boss. The special idea is how the church is run: not by a pope, and not mainly by bishops, but by elders. Presbyter is an old church word for an elder, a person chosen to lead and to watch over a congregation. A person in that church is a Presbyterian; Presbyterianism is the system and the faith, the “-ism.” In everyday talk people mostly say “She is Presbyterian,” and that is the word you will hear. In Scotland this tradition is the national church (the Church of Scotland). In the United States it is one of the old, well-known Protestant families, and it shaped schools and public life for a long time — though actually, if you only count people in the pews today, Baptists and many independent churches are larger. And though the tidy label sounds like one church, Presbyterian churches do not all agree. They share that elder-led pattern, and then they argue, as churches do, about how strict to be, who may be a minister, and how to read the Bible.

長老宗；台灣日常多說「長老教會」，常特指台灣基督長老教會。