What is ShowWindow() in VC++ Win32 application? Why we use ShowWindow()?

hi..
After the CreateWindow call returns the window has been created internally in windows. However the windows do not yet appear on the video display, two more calls are needed. They are:

ShowWindow(hwnd,nCmdShow);

UpdateWindow(hwnd);

The ShowWindow call determines how to display the window on the screen, whether it is normal, minimized or maximized. The first argument is the handle to the window just created by CreateWindow. The second argument nCmdShow is the value passed as a parameter to WinMain which determines how the window is to be internally displayed on the screen whether it is normal, minimized or maximized.