Wow beautiful photo. Where was it taken? City of London can mean just London as a city. Then you would use the term “ city of London “ to refer to a historical and financial district. It is a special area also referred to as “ a square mile” as it is just slightly over a square mile. See photo. You can also refer to Westminster as “ city of Westminster” but just these 2 no other boroughs! It is marked with silver dragons with shields as a historic heritage to symbolise the importance of protecting the “city of London” London has many areas, we call them BOROUGHS. The more central are Greater London ( city of London, city of Westminster Islington, Chelsea …….) and the ones just outside are Outer London. There is a list for both of them, you can Google it if interested in specific boroughs.

London is a city. Greater London is a county. A county is made up of a number of towns, villages, and maybe a city. Examples are Greater Manchester, Yorkshire, and Lancashire.