Where did Java come from?
The origins of Java can be traced back mainly through the C and C++ languages. The C programming language was one of the first "Portable" languages, meaning that it could run on many different types of computer. The C++ language was like C but included the ability to create classes, one of the central ideas behind Object Orientation. The designers of Java decided to take advantage of the number of users who understood C++ and designed the language to be easy for C++ programmers to use.
Java was designed to be easy for C/C++ programmers to learn
Although C and C++ programs could be portable, they needed to be re-compiled for each system that they were to run on. Thus the executable program created for a Linux computer could not run directly on a MS Windows computer.
To be able to run on a different machine such programs needed to be re-compiled for the target machine. This could often be a complex and error prone process. By contrast, Java programs are what is called binary portable.
Java programs are binary portable, they run on different platforms without re-compilation.
Thus the output of the compilation process can be run directly on target machines with no further intervention.