I did say that. In the US a query is kind of a pitch for the novel (catchy but brief synopsis, publishing/biographical info, salutation and contact info) and a cover letter is just what you said. "For your consideration, here is my novel The Big Cheese, of approximately 1 million words. Thank you for your time."
But I don't know if that terminology is different in Canada. (Since EMaree is saying that covering letter/query letter in the UK are the same thing.)
Some agents link to articles about how to format the materials they want, perhaps that could help you figure out which type of letter they want?
Nicola Morgan has a series of books (especially "
Dear Agent") that cover the UK style of covering letters much better than I can, including a break down of what all goes into the letter.
A UK covering/cover letter also contains a pitch sentence (or pitch paragraph) that serves the same purpose as the plot summary in a US query. It's also more focussed on formalities than a US query letter is.
I've had a good experience submitting in the UK using a modified version of a US query -- slimmed down plot (2 short paragraphs), and more formalities. I went against the standard 1 paragraph pitch that's recommended, but the UK agents I spoke to were easy-going about the letter formatting and just wanted something short (1 page max), interesting, and clear to read.
In my experience the biggest difference between UK and US is: UK agents are known for making their decision based on the sample chapters rather than the letter, but in the US you can be rejected on the query alone.