A concordat is an agreement between the Catholic Church and a specific State that establishes guidelines for cooperation between the two for the purpose of mutual benefit.
The most binding and most relevant agreement in Church-State relations is the concordat and is usually made with countries of great Catholic tradition. There are numerous countries with agreements with the Catholic Church in one way or another. The agreements do not necessarily have to go hand in hand with the figure of the concordat, but there are also partial and sectoral agreements or simple diplomatic relations.
The Catholic Church maintains diplomatic relations with 174 sovereign countries, only with 17 does not have any type of relationship, of these, nine are Muslims and four communists.
The one considered first Concordat dates from 1122, between Pope Calixto II and the German Emperor Enrique V, whose purpose was to end the complaint of the investiture, a the dispute between Rome and the Holy Empire over the appointment of senior officials ecclesiastics. Although the concordats have a very distant origin, most of them are signed in the 19th and 20th centuries.
Concordats have very diverse content, they deal with many subjects: culture, taxation, education, etc.
They usually establish the right to be able to teach religious education in schools, guarantee the recognition of the Catholic Church and freedom for worship and its development. Some concordats and agreements also regulate the exemption by the Church from paying some taxes.