How does the UK election work?

Millions of people are expected to cast their ballots in Thursday's UK general election that will decide who runs the country.
The poll is voters' first chance since December 2019 to decide who should represent them as their local Member of Parliament, or MP, in Westminster.
Most will choose their preferred candidate in person at polling stations across England, Scotland, Wales and Northern Ireland.
Others have already done the same job using postal votes.
Here are some of the key things to know.