Catholics are the main "sect" if you will of Christians. It is my belief and if I've learned correctly, proper history, that Jesus started the Catholic Church through Peter, the first Pope. This belief may differ in other denominations. MOST Protestant Churches, if not all, started by divulging away from the Catholic Church in schisms because they disagreed on certain issues (be it Saints or imagery, etc)
Catholics are consistly more traditional and old-fashioned than other denominations, which can be good or bad depending on your POV.