What does the queen represent?

You may want to narrow down your question to one jurisdiction!

In the United Kingdom, Her Majesty performs most functions personally as the head of State; however, the Lords Commissioners have the authority to represent the Queen, as do the Lord Lieutenants as ceremonial representatives. Throughout the rest of the Commonwealth realms, the Queen is represented at a national level by a Governor General (some realms use the term Governor-General with a hyphen), and some realms also represent the Queen at provincial or state levels (such as the Lieutenant Governors of the Canadian provinces).