​​​​Parishes are an essential component of the universal Church, which Catholics profess to be the one, holy, catholic, apostolic Church. Every member of the Church faithful, through faith and baptism, becomes a member of the universal communal body. This universal Church, one in faith and in union with the Holy Father, is realized in several "autonomous" churches reflecting Eastern and Western traditions. Spread around the world, these autonomous churches consist in various subgroups, such as dioceses, in order better to address the local circumstances in which the universal Church finds itself. While the faithful generally associate with a particular parish in their home diocese or archdiocese, as the core reference of their Church community, it is also important to remember that the faithful are in fact direct participants in the universal Church and are welcomed in that Church, wherever they may be. It is the communal understanding of the faith that allows Catholics to be "at home" anywhere wi​​thin the Church and in their immediate relationship with the communion of the faithful.

In Los Angeles, the first parish communities for the faithful were the missions. Later, as organized civic communities were established, other geographically based parishes were founded. In the 20th century, with the burgeoning population particularly in the Los Angeles area, the archdiocese began to set parish boundaries such that families would not need to walk, or later drive, more than about a mile to their parish church. The establishment of new parishes and the founding of schools at the parishes were regularly announced by the archdiocese. More recently, the trend has been to expand existing parishes and to recognize centers that are serving the needs of particular national groups.

As noted in Parishes, Missions, Oratories, and Centers, a parish is a community of the Christian faithful established on a stable basis (Canon 515). Each parish is a "juridic person" under canon law, with certain defined rights and obligations, both as a separate canonical entity and as a part of the archdiocese. In all cases, parishes are subject to the overall responsibility and authority of the archbishop. Each parish has the right to acquire, retain, administer, and alienate (sell, lease, or transfer) temporal goods as regulated by canon law (Canons 515.3, 1255, and 1256), but that right is subject to parallel constraints and rights under civil law. Similarly, under both canon and civil law, every parish is obligated to administer and steward its assets for the current and long-term benefit of the parish and the faithful.

Fundamentally, under canon law all parish assets belong to the parish and are held for the benefit of the parish and the faithful (Canon 1257.1). The pastor/administrator, under canon law, has the lead responsibility for the parish operations, the oversight and stewardship of the parish assets, and the pastoral and spiritual care of the faithful (Canons 519 and 532).