The Show method displays a window that’s open, but invisible.
window.Show
• window – A window object.
A window can be open, but still invisible. To check whether a window is open, but not necessarily visible, use the window’s IsLoaded property.
You can make a window invisible using the window’s Visible property (window), the window’s Hide method (window), or the OpenVisible parameter of the window’s BeforeOpen event.
When you open a window, the accounting system implicitly opens all the windows in the form invisibly, then displays the first window in the form (the parent window). The child windows in the form remain invisible, but loaded. You can use the Show method to selectively display these child windows without explicitly opening them.