Live View is the default screen you will see while viewing your channels. It displays the live video feed. 

Use the mouse and right click anywhere and bring up the Quick Menu.

If you’ve selected a layout that enables viewing multiple channels, you can rearrange where the channels display by dragging and dropping the channels on the screen’s layout.

You can also double-click on any channel to toggle between Single View and Multi View options.  Multi View options will let you view all of your cameras simultaneously.