West London is a sub region of Greater London consisting of the London Boroughs of Brent, Ealing, Hammersmith and Fulham, Harrow, Hillingdon, Hounslow and Richmond upon Thames.

West London had a gross value added of 34.4 billion Pound Sterling in 2007, around 20% of the gross value added of Greater London. London Heathrow Airport is a major employer in West London and the University of West London has more than 47,000 students.

East London is a popularly and informally defined part of London, capital of the United Kingdom, lying east of the ancient City and north of the River Thames.

East London comprises the whole of six modern London Boroughs – Tower Hamlets, Newham, Waltham Forest, Barking and Dagenham, Redbridge, Havering – and the greater part of a seventh, Hackney.

The East End of London is a subset of East London, consisting of areas close to the ancient City.

The Eastern (E) Postal District is a different subset of East London and there is also an "East" sub-region used in the London Plan for planning and progress-reporting purposes. The most recent (2011) iteration includes the seven boroughs north of the Thames with the addition of three boroughs south of the river.