Canon is a Greek word that simply means rules, norms or the standards. Canon comes from a Greek word kanon that denotes a straight rod which before was used for measuring stick and eventually came to mean norm or rules. Canon law has been in existed for 2000 years. Canon law is used in Catholic churches that give the order, discipline, the structure, rules, and rules to be followed. Catholic Church has two codes that is one for Latin Church and one for Eastern Catholic churches. The universal legislator for Catholic churches is the Pope and the official language of canon is Latin. Canon law guides the church as a large human from differing in the cultures and languages. Canon law informs the Catholic faithful how to conduct themselves and how to protect the rights of the faithful. Canon law plays a major role in shaping marriage and family life. Canon law is made and enforced by hierarchical authorities of the said church. Canon law was one of the early modern western legal systems and still, it is the oldest functioning legal system. The canon law has four periods namely the jus novum, jus antiquum, jus novissimum and codex luris canonici. Jus antiquum extends from the beginning of the church to Gratian time. Jus novum is from the period of Gratian to Council of Trent. Jus novissimum is period between Council of Trent and promulgation.