Close:
1. Close this form only
2. When close is a main form, the program exits.
3.Close Formclose event occurs, Formclosequery event
4. Main form close after the program is Application.terminate
5. After the subform is close. You can show it without releasing it.
6. It is also said that the close method of the main window is actually called application's terminate to terminate the program.
Halt:
The Formdestory event occurs to forcibly terminate the execution of the application and return to the operating system (abnormal exit mode).
Application.terminate:
1. is to close the entire program, including all forms.
2.application.terminate above three events will not happen application.terminate is the end of the program.
ExitProcess (0):
1. Direct and clean termination procedures.
2.MSDN Information
Https://msdn.microsoft.com/library?url=/library/en-us/wcekernl/html/_wcesdk_win32_exitprocess.asp
Tutorials-close, Halt, terminate, exitprocess differences