Full communion is a term used in Christian ecclesiology to describe relations between two distinct Christian communities or Churches that recognise that each other shares the same communion and the same essential doctrines. That does not mean that there would be no differences at all between them.
- The Roman Catholic Church (which follows the so-called Latin Rite) is in full communion with the Chaldean Catholic Church, for example. The Chaldean Catholic Church follows the East Syrian tradition. In other words: Both churches celebrate mass differently, but they agree completely on all ideas.
- The Roman Catholic Church is in partial communion with the Protestant Churches. There are many things both Churches agree on; but in some things they are different; As an example: a Catholic priest can forgive sins; a Protestant priest cannot.