Thanks for adding the images Matvey.
As to your second question I should say, sometimes we only wire one line (+) and one natural (-) from the terminal blocks to the PLC modules and use the rest of the terminals for powering other equipment that we have in the panel. In this situation, we simply jump the the powers from the CPU to the next module and then to the next module. This will continue until the last module that we have on that rack.
So the second wires that you see for the CPU is just a jump that goes to the next module.
These are just different ways of wring and powering the PLC module but one thing to take note of here is that each and every PLC module and equipment that you have in the panel needs a separate power from the power supply. In most cases when we have a lot of equipment in the panel, we even use several power supplies to be able to power all the equipment in the panel.
Here is a YouTube video from RealPars on redundant power supplies. I think watching this video gives you more insight about the using power supplies in the electrical enclosures in general.
Let me know if you have more questions.