What is a "buffer zone"?

A "buffer zone" is indeed best defined as a transitional zone between a residential zone and a commercial zone. These zones are designed to provide a separation between different types of land uses, which can help manage the impact of one type of use on another. For instance, the buffer can reduce noise, traffic, and other negative effects associated with commercial areas on the surrounding residential neighborhoods. This transitional space can include parks, landscaping, or lower-intensity uses that create a smoother shift between the two more intensive land uses.

In contrast, options such as a permanent barrier preventing urbanization or a zone restricted to industrial development imply a more rigid or exclusive nature, which doesn't capture the flexibility and purpose of a buffer zone in urban planning. Similarly, a designated area for public parks only limits the definition, as buffer zones can serve multiple functions beyond simply being park land.