The Window menu has options that support the Multiple Document Interface and let your work with multiple web pages.
The first four options arrange the child window in various ways:
Cascade shows them all the same size but staggered so you can see the title bars.
Tile Horizontal arranges all the windows horizontally across the workspace, perhaps in multiple rows.
Tile Vertical arranges all the windows vertically across the workspace, perhaps in multiple columns.
If you've minimized any of the child windows, Arrange Icons arranges the icons on the bottom of the workspace.
The Close All Windows command closes all the child windows.
The remainder of the Window menu lists all the child windows. You can select any of the windows to bring it to the front.