What is meant by platform independent?

Answer 1

A computing platform is the environment in which a piece of software is executed. It may be the hardware or the operating system (OS), even a web browser or other underlying software, as long as the program code is executed in it.
Cross-platform software (also multi-platform software or platform-independent software) is computer software that is implemented on multiple computing platforms. Cross-platform software may be divided into two types; one requires individual building or compilation for each platform that it supports, and the other one can be directly run on any platform without special preparation

Answer 2

It can run on Windows, Linux, Mac OSX, Android, etc. Desktop, mobile, etc.

Answer 3

It doesn't matter what you're using, a Mac computer, a Windows laptop, a mobile phone, or a Linux computer, your Java program will work on all.