What is InputStreamReader And BufferedReader and for what purpose it is used

Answer 1

https://docs.oracle.com/javase/7/docs/api/java/io/BufferedReader.html

Answer 2

It is basically another way of taking user input apart from Scanner class.

It generally takes the input as a character stream and reads from it.

Here is a simple example.
https://code.sololearn.com/cL5YR3CMiOo8/?ref=app