differences in packages

Question

what are the differences between io package and lang package in java
I.e differences between java.lang.*; and java.io.*;

Answer 1

Java.lang "provides classes that are fundamental to the design of the Java programming language."
https://docs.oracle.com/javase/7/docs/api/java/lang/package-summary.html

Java.io "provides for system input and output through data streams, serialization and the file system."
https://docs.oracle.com/javase/7/docs/api/java/io/package-summary.html

Answer 2

You use these packages to import specific features to your class. And depending on tge features you need you have to import it by its path or package.
eg java.io handles with io streams

Answer 3

I know that but what are the differences between these 2 packages?!