Placing a block on top of others, how to implement?

Question

css

In the screenshot, I circled the block screenshot.ru/4b74925063c7b0fe4bd088c2e361acde , I don’t understand how to do it. It sticks out on the upper and on the lower block. But under it there is another block, as I understand it, with a background. How to implement it?

Answer 1

See z-index