Certain areas within in a bathroom are defined as Bathroom Zones, or more specifically zones within a room containing a bath or shower.
These zones are not restricted to just bathrooms, the zones also apply to any room which contains a bath or shower, for example a shower in a bedroom.
Bathroom zones do not apply to emergency facilities such as emergency showers used in industrial areas or labs.
Bathroom zones also determine what electrical equipment can be installed, and the minimum specification and IP rating of the electrical equipment within a each zone, see Bathroom IP Ratings.