A cathedral designates the place where a bishop resides, and a church is a more common term for buildings where Christian worship takes place.
Catholics will often use the words cathedral and church to denote various sites of Christian worship. However, at times it can be confusing, especially if you are not familiar with the terms.What is the difference between a church and a cathedral?
The name “cathedral” is given to churches that are the “hub” of each diocese, where the bishop typically presides at important liturgies. The cathedral gets its name from the presence of the bishop’s chair, traditionally called the cathedra (Latin word for “chair”). The bishop sits on this chair when celebrating the Mass or other liturgical events at the cathedral. Another Latin word, sede (“throne”), is where we get the term “see” for the territory under a bishop’s authority (a diocese or archdiocese).
In each diocese there is usually only one cathedral, and often the local cathedral is also the oldest surviving church in the area. This is not always the case, but in most situations the largest and oldest church building in an area is designated as the cathedral.
The word “church” most commonly is used to refer to any physical building where Christians gather for public worship. This is why a cathedral is also a church, but not all churches are cathedrals.
More broadly, the term can also be used to denote a “community” of believers, as it is explained in the Catechism of the Catholic Church.
In Christian usage, the word “church” designates the liturgical assembly, but also the local community or the whole universal community of believers. These three meanings are inseparable. “The Church” is the People that God gathers in the whole world. She exists in local communities and is made real as a liturgical, above all a Eucharistic, assembly. She draws her life from the word and the Body of Christ and so herself becomes Christ’s Body. (CCC 752)
Both words have rich meanings, but are used differently depending on the circumstance.