A more thorough explanation:

A legal subdivision is the division of a tract of land into smaller parcels using legally recognized methods for surveying and recording the results. This process is approved by the government and follows local subdivision regulations.

For example, a developer who wants to create a new housing development must follow the legal subdivision process. They must survey the land, create a plat map, and record the results with the local government. This ensures that the new parcels of land are properly defined and recorded.

On the other hand, an illegal subdivision is when a developer divides a tract of land into smaller parcels without following local regulations. This can lead to issues with zoning and land planning, as well as potential legal consequences.

Overall, legal subdivision is an important process for ensuring that land is properly divided and recorded, and that developers follow local regulations.