Superlatives are words that show the highest degree of something, like 'biggest' or 'fastest'.
Using superlatives can show excitement or importance about something.
Examples:
The elephant is the biggest animal.
She is the fastest runner in the race.
He is the smartest person in the class.
That's the funniest joke I've ever heard!
This is the most delicious cake in the world!
She is the kindest person I know.