What was a purpose of zoning laws

The basic purpose and function of zoning is to divide a municipality into residential, commercial, and industrial districts (or zones), that are for the most part separate from one another, with the use of property within each district being reasonably uniform

Its primary purpose is to segregate uses that are incompatible.

Explanation:

This means that with different zone or districts will be like personalised laws for each of them. So, this particular regulations could be like an decentralised system, when according the needs, restrictions and laws are provided.