Open Source ( What is this?)

As a user of a software you can not see the original programing code of an application. Because when a program code written by a program language it is need to be complied. With out compile a program can not run. When a programer write a program in a human understandable program language the hardware can not understand it, to execute that program you need to convert those human understandable language to machine language. The conversion a program from program language code to machine language is called compile process. A user can not understand  Machine language so that he can not know the original program language code and he can not make any change in the program. The concept of Open Source comes to break the limitation of a program source code. Open Source gives user to read the original source code and grant right to change the program as user demand.