Hi Girish,  If you are expecting the general idea of java , then it is a programming language. This language becomes more popular because of its independency on machine and JVM.

Java is used to create the applications. It is used in Android app, server apps, software tools etc.

Amezon , google , netflix and many more companies are in market those are using java. And provides the palcements to the students on java basis.

I hope it will help.

Thanks.