Region - A sub-national administrative unit comprising of several provinces having more or less homogenous characteristics, such as ethnic origin of inhabitants, dialect spoken, agricultural produce, etc.
Province - The largest unit in the political structure of the Philippines. It consists, in varying numbers, of municipalities and, in some cases, of component cities. Its functions and duties in relation to its component cities and municipalities are generally coordinative and supervisory.
City - There are three classes of cities in the Philippines: the highly urbanized, the independent component cities which are independent of the province, and the component cities which are part of the provinces where they are located and subject to their administrative supervision. (see City Classification)
Municipality - Is a political corporate body which is endowed with the facilities of a municipal corporation, exercised by and through the municipal government in conformity with law. It is a subsidiary of the province which consists of a number of barangays within its territorial boundaries, one of which is the seat of government found at the town proper (poblacion).
Barangay - The smallest political unit into which cities and municipalities in the Philippines are divided. It is the basic unit of the Philippine political system. It consists of less than 1,000 inhabitants residing within the territorial limit of a city or municipality and administered by a set of elective officials, headed by a barangay chairman (punong barangay).