Well…
First picture is the Network Operations room. aka My Office.
From left to right are: UPS batteries, the UPS, the Power Distribution cage (with main breakers in front, and rack breakers in the back), then my rack for servers, then the last rack will be filled with network switches and cables.
2nd pic is the status display on the UPS
3rd pic is a close up of the 16 batteries in the bank, 50 lbs each.
4th pic is the Automatic Transfer Switch. In the event of a power failure, the ATS starts the generator and then turns a massive switch inside that connects a 400 amp line to the generator. When the main power comes back on, the switch turns back and shuts the generator down. The UPS keeps the data center alive during the transitions.
The last picture is the server colocation room where other companies pay to put their servers. That’s what I do right now in another center, I actually pay for part of a ROOM.. not just a rack. Here there are 1/3 racks on the left, 1/2 racks in the middle, and full racks in the back. So depending on how much equipment a company has, they rent the space they need.