Yes. This is an enhanced feature of System 7. It prevents active windows from getting in your way while you are moving icons.
To make a window active, simply click the window. If you click an icon, the window activates when you release the mouse button. If you click elsewhere in the window (not an icon), the window activates when you press the mouse button.
This is different from System 6, in which windows are always activated on mouse-down.
This allows you to move an icon from an inactive window to another window without having the inactive window become active and possibly cover other items on your desktop.
Moving an icon from an inactive window to another inactive window leaves the currently-active window active. This way you can move an icon from an inactive window to an inactive window without making either active. Also, if you want to move a window without making it active, hold down the Command key and drag the window (by clicking in the title bar).