The Church refers to itself by several different terms depending on who we are having talks with  Internally Catholic Church seems to be most prevalent but so too is Church of God Church of Christ or the Church of the Saints in that all Saints in Heaven are considered members  Legally the word Ecclesia is all that need be used and is all that is used in Cannon Law as well as how the Church describes itself in the legal code of other countries  The other names are then really just descriptions or agreed upon local language lingo  Officially this Latin word consist of the name of the Church and is translated as The Church and even the Eastern Catholic Churches are legally described with this  The Greek word of same meaning and origin is not held to be propiatary by the Church