650 constituencies (or districts), somewhat like our Congressional Districts but much smaller and of irregular size in terms of population.
Multiple significant parties, not simply two. The Conservatives are like the establishment Republicans and the UK Independence Party i(or UKIP) is like the Tea Party.
With multiple parties splitting the vote, winners in many districts often have much less than 50 percent of the vote. In England, it’s the Conservatives versus the other conservatives versus the moderates (Liberal Democrats) versus Labour (left-of-center). Even more complex are the “nationalist” parties in Wales and Scotland. And don’t even ask about Northern Ireland. Prior to the last election, all this complexity didn’t matter much. Every election was Conservatives versus Labour. Now, things are all jumbled up.
Once the election is held, the party with the most seats (if less than a majority) will try to find enough partners to have a majority. In their system, the equivalent of Speaker Boehner is the head of government. There is no separate President, and the monarch nowadays is more of a figure head as head of state.
They’re called ridings - both the UK and Canada have a lower house styled the House Of Commons.
Thanks!! Thank to everybody else who answered too. FR is better than Britannica lol. Are they still around? Interesting political process.