(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.