The geographic region in south central Ontario that includes The City of Toronto and surrounding areas:

Ajax
Brampton
Concord
Markham
Mississauga
Oshawa
Pickering
Richmond Hill
Toronto (Etobicoke/East York/North York/Scarborough/York)
Thornhill/Vaughan
Whitby

On a sattelite photograph, the Greater Toronto Area can be seen as a densely populated area that runs along the central north shore of Lake Ontario.