unitary- constitution which establishes that legal sovereignty resides in one location. Power can be delegated to subsidiary bodies but this power can be returned to the sovereign body
federal constitution- is where legal sovereignty is divided between the central government and regional government and the powers are protected by an entrenched constitution
in the UK the ultimate political power rests in one geographical location which is Westminster
in Westminister all important political institutions are located here such as parliament, supreme court and other government departments