This mod adds "Cursed Camera" research underneath "Optics".
Once researched, craft your choice of 1, 2, 4, 6 or 8 cameras in the logistics section of the inventory crafting menu.
Once crafted, click the item. Then press the pencil/edit button, stand somewhere important and set the camera.
This adds a static view of area where you set.
If you selected 2/4/6/8 cameras, you'll have 2/4/6/8 pencil/edit buttons to use to add views of other areas. Then, later on, wherever you are on the map, simply select the camera item from your toolbar/inventory, and a 'live feed', like a surveillence camera, comes up, showing you the view you had captured earlier.
It's literally like buying a CCTV system, installing the cameras, then viewing a live feed of those cameras anywhere in the world. Great for keeping an eye on defences, power, whatever.