Which body is known as the lower house of Parliament in the UK?

The House of Commons is known as the lower house of Parliament in the UK due to its significant role in law-making and representing the public. Members of the House of Commons, known as Members of Parliament (MPs), are elected directly by the people in their constituencies, which enhances their accountability to the electorate. The House of Commons has the primary responsibility for proposing and debating legislation, and it holds the government to account through various means, including questioning and debates.

In contrast, the House of Lords serves as the upper house, where members are not elected but are appointed based on various criteria, such as expertise or hereditary positions. The Senate is a term used in other countries, particularly the United States, to describe their upper legislative chamber, while the Parliamentary Assembly is not a term typically associated with the UK Parliament. Therefore, the House of Commons is rightly identified as the lower house due to its foundational role in the UK's democratic system.