Cal. Gov. Code § 66424

“Subdivision” means the division, by any subdivider, of any unit or units of improved or unimproved land, or any portion thereof, shown on the latest equalized county assessment roll as a unit or as contiguous units, for the purpose of sale, lease or financing, whether immediate or future. Property shall be considered as contiguous units, even if it is separated by roads, streets, utility easement or railroad rights-of-way. “Subdivision” includes a condominium project, as defined in subdivision (f) of Section 1351 of the Civil Code, a community apartment project, as defined in subdivision (d) of Section 1351 of the Civil Code, or the conversion of five or more existing dwelling units to a stock cooperative, as defined in subdivision (m) of Section 1351 of the Civil Code.