Downing Street
In short
Downing Street is a gated cul-de-sac in Westminster, London, that serves as the official home and office for the UK Prime Minister and the Chancellor of the Exchequer.
In plain words
It is a famous street near the Houses of Parliament. The most important government leaders live and work in the buildings located there.
A simple example
When a new Prime Minister is appointed, they move into Number 10 Downing Street to begin their job.
Why it matters
It is the centre of British political power and a global symbol of the UK government. Most major national decisions are made within its buildings.
Easy to mix up
People often confuse the street itself with Number 10, which is specifically the Prime Minister's residence.