1) Will every software requires a c++ or any coding program to run?
2) I understand visual Basic helps in creating the GUI for software they create.
3) How do they create a link between the c++ program and GUI so that if You click some button it performs the calculation for you.
I think I was clear with my question.
If not please let me know so that I can elaborate my question.
A GUI library is used as part of the C++ programming language. C++ programming software is usually a suite of software which consist of an Editor, compiler and debugger.
Depending on platform, like windows or linux, the gui library can be of different forms. Windows using Visual C++ will use the native library of windows. If I use another C++ suite I would use something like wxWidgets or Qt4. On linux I could use wxWidgets or Qt 4 as the GUI library. All of these take a learning curve to get a basic up and running. Visual studio and visual c++ might get you the fastest start.
All applications start the same basic way. They start with a mainline which accesses a gui library to access the GUI. What the application does from that point varies greatly and is part of the functionality that you are trying to achieve.
There are plenty of tutorials for all the gui libraries and how to set up the c++ suite up for each platform.