system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What's the difference between the UK Government and Parliament?
gpt
Parliament is the overall institution consisting of two houses - the House of Commons, elected by the people, and the House of Lords, who are appointed and serve for life. They both meet in the Palace of Westminster in London, they both draft and vote on legislation, but generally all of the political power is in the Commons - because they're elected. 

Within the House of Commons, the party (or coalition) who has the most seats *generally* forms Her Majesty's Government - their leader is Prime Minister, and the cabinet is made up of members of that party (or coalition). The next largest party/coalition in the Commons who isn't part of the government forms Her Majesty's Loyal Opposition - their job is to present the other side of arguments and ensure that the Government is doing things properly and justifying their decisions.

Currently Her Majesty's Government is the Conservative Party, who have 329 out of 650 seats, and their leader, Theresa May, is Prime Minister. The Opposition is Labour, who has 231 seats, and the remainder of the House is made up of other parties (next largest is Scottish National Party with 54).