Administrative Geography
Administrative geographies (e.g. Local Councils, District Electoral Areas and Electoral Wards) are hierarchies of areas relating to national and local government in the UK. This hierarchy is complicated because there are several layers and the structure is different in each constituent country of the UK. In addition the boundaries of many of the layers in the hierarchy are subject to periodic or occasional change.
Statistical Geography
Smaller units (Super Output Areas and Small Areas) have been created below the administrative areas for statistical purposes.
NISRA Geography Factsheet