Residents of the UK: What role does the minority (opposition) party play in parliament?

Question

As this American understands it, the Prime Minister and his Cabinet all come from the majority party in Parliament.

Answer 1

Your understanding is correct but remember that because there are more than 2 parties there can be a minority government or a majority government. The labor party is currently a majority which means the number of members of parliament it has is more than those of all other parties combined which makes it easier for the to win a vote on something like a new bill if its members do not go against the leadership wishes. The opposition party (and others) are their to question and challenge the governing parties behavior and for the most part try and organize enough support to defeat the government in votes on things like the recently mentioned new bills.

When there is a minority government, quite often the opposition parties will team up to defeat and block the governments wishes.

The Shadow "insert title here" is a shadow of a cabinet position filled by the leading opposition party (the opposition party with the most members of parliament). They are responsible for policy definition and advice to the leader of the opposition party and technical would fill those positions in the cabinet should they take over government at any time.

Answer 2

As a follow up to that from another confused American I have two questions: What is a "shadow secretary" and what to they do?"  I think it has something to do with the minority party; but I can't understand how they perform any "shadow" functions without access to the same materials as the "actual secretaries."