Superlative:

She is the smartest student in the class.This is the tallest building in the city.That was the most delicious meal I have ever eaten.He is the fastest runner on the team.This is the most beautiful sunset I have ever seen.

Comparative:

She is taller than her sister.This book is more interesting than the last one.He runs faster than his brother.This dress is prettier than the one she wore yesterday.Their house is bigger than ours.