(a) For the purposes of this article:
(i) "Commission" means the planning commission authorized by W.S. 15-1-502;
(ii) "Street" includes streets, highways, avenues, boulevards, parkways, roads, lanes, walks, alleys, viaducts, subways, tunnels, bridges, public easements and rights-of-way and other ways;
(iii) "Subdivision" means the division of a tract or parcel of land into three (3) or more parts for immediate or future sale or building development.