The Concentric Zone Model is an urban model designed by Ernest Burgess which suggests that cities grow outward from a central area in concentric rings, like the layers of an onion.
Transition Zone: An area of mixed commercial and residential land uses surrounding the CBD.
Outlying Residential Area/Suburbs: Areas located outside or on the edge of main urban areas primarily composed of residences.
Commuter's Zone/Rural Fringe: The outermost ring where people commute into the urban areas for work.