In reading books, I know how a window is created, and I think I know how to create a menu toolbar (File, Edit, View, etc) across the top of the screen.

But, how does a Windows application like Excel or Word create everything else you see on the screen? In Excel, how would you draw the formula cells? In Word, how would you draw the text you see?

On really old computers, I remember that the screen is a bitmap, and you just manipulate the corresponding memory locations.

Can anyone tell me how this would work in a windows app?

Thanks!