The task of spatial planning is to allocate land to a building zone. If, in the course of the allocation, it is decided to reallocate building land that has not yet been built on and will presumably not be needed for the next 15 years to the agricultural zone, for example, the process is called rezoning. If the landowner is awarded compensation for the rezoning, the process is called zoning out. 

If the allocation were opposite, it would be zoning.