Question

What is classification? How is it useful?

Answer 1

Grouping of things with similar properties is called classification. We can classify different things based on whether they are living or non living, metals or non-metals. It is also possible to classify objects based on their size, solubility in water etc.
By classifying things/objects we can make our work easy. For example an alphabetic classification of books in the library makes it easy to retrieve a certain book needed.