Favourite means number 1 in your opinion.
It is similar to the word like but it is asking for your best pick.
What food do you like?
Can have a range of answers.
What is your favourite food?
Should only have one answer.
Some people do answer with more than one thing but the main idea is there is only one answer.
Let’s look at the structure:
My favourite food is curry.
We use the personal possessive with favourite.
I – my favourite
you – your favourite
He – his favourite
she – her favourite
we – our favourite
they – their favourite
it – its favourite
Look at the mind map:
You can ask any number of questions with favourite.
What’s your favourite movie genre?
It’s science fiction.
What’s your favourite fictional book?
Too difficult, my favourite author is Philip K Dick but I can’t choose which of his books I like the most.
What’s your favourite superhero comic?
I’m not really into superhero comics. I love batman though. I also like X-men.
What’s your favourite wild animal?
My favourite wild animal would have to be a tiger.
What’s your favourite pet?
Well, I’ve only ever had cats.
What’s your favourite animation TV series?