What are comparatives and superlatives in English grammar?

[PercyColli]

I'm having trouble understanding how to use comparatives and superlatives correctly. Can someone explain the rules and give a few examples?

 

[SkyDrifter]

Things are compared by way of comparatives and superlatives.

Comparatives are used to compare two things and mostly they end in either -er or more.
For example, this book has less paging than this one.

Superlatives are used to compare three or more things and they usually end on -est or with most.
For example, this book is the shortest book in the world.

 

[sophie]

Comparison is done with the help of comparatives and superlatives. Comparative involves the comparison of two things (e.g. taller, smarter), and superlatives entails more than two things, which means the largest (e.g. tallest, smartest). The difference on quality, quantity or degree are defined by them.