Dictionary, Census of Population, 2021
Core, fringe and rural area

Release date: November 17, 2021Updated on: February 9, 2022


The terms 'core,' 'fringe' and 'rural area' distinguish between population centres (POPCTR) and rural areas (RA) within a census metropolitan area (CMA) or census agglomeration (CA).

CMA or CA can have two types of cores: the core and the secondary core. The core is the population centre (POPCTR) with the highest population, around which a CMA or CA is delineated. The boundaries and population counts of the population centres (core) used to delineate the CMAs or CAs are taken from the previous census. The core must have a population of at least 50,000 persons in the case of a CMA, or at least 10,000 persons in the case of a CA.

The secondary core is a population centre with at least 10,000 persons (based on the previous census) and that is within a CMA or CA, but outside the main municipality (census subdivision) that contains the core. The secondary core can also be the core of a CA that has been merged with an adjacent CMA.

The  term 'fringe' is explained in two ways. First, by not being able to have two cores within the same census subdivision (CSD), other population centers within a CSD that already have a core or secondary core are defined as 'fringe' even if their population is over 10,000 persons (based on the previous census). Second, a fringe includes all population centers within a CMA or CA that have a population of less than 10,000 persons (based on the previous census) and are not adjacent to the core or secondary core. All territory within a CMA or CA that is not classified as core or fringe is classified as 'rural area.'

Reported in

2021, 2016 and 2011


While every CMA and CA has a core, it may or may not have a secondary core, a fringe or a rural area. See Figure 1.12.

Population counts for population centres are published according to the class of population centre, regardless of whether they are inside or outside a CMA or CA. Population centres are classified into one of three groups, depending on the size of their population:

Refer to the related definitions of Census Metropolitan Area (CMA) and Census Agglomeration (CA), Population Centre (POPCTR), and Rural Area (RA).

Changes prior to the current census

For the 2011 Census, the terms 'core,' 'fringe' and 'rural area' replace the terms 'urban core,' 'urban fringe' and 'rural fringe.' These terms distinguish between population centres (POPCTRs) and rural areas (RAs) within a census metropolitan area (CMA) or census agglomeration (CA).

Prior to 2011, the terms 'urban core,' 'secondary urban core,' 'urban fringe' and 'rural fringe' were used.

Beginning in 2001, the concept of the secondary urban core was used to describe the urban core of a CA that merged with an adjacent CMA.

Beginning in 1996, the term 'urban core' replaced the term 'urbanized core.' The term 'urbanized core' was used from 1971 to 1991.

Prior to 1996, this concept was known as CMA/CA parts.

Beginning in 1986, primary CMAs (PCMAs) and primary CAs (PCAs) were delineated within some CMAs and CAs. Because of this change, some urban areas that were urban fringes of 1981 CMAs or CAs became urban cores of 1986 PCMAs or PCAs.

For 1976 and 1971, the urbanized core was further broken down into the 'largest city' and 'remainder.'

For 1966 and 1961, the urban part of the CMA was divided into the 'metropolitan area – urban' (continuous built‑up area) and the 'metropolitan area – outside urban' (non‑continuous built‑up area); the remaining rural part was known as 'metropolitan area – rural.'

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