How to create this section?

I’m learning HTML and CSS. So, I downloaded a free PSD template to practise. And I don’t understant how to create this section (inside of the red frame). How to set a carousel as a background and how to make the edges of the photos always be on the green line?

The best way to make that is to use CSS Grid. If you don’t want to do that, then Flexbox will help too but i prefer to use CSS Grid.
Also if you are not familiar with both of these then there is only one option left that is to use position property, you can align them to the position you wanted using position element… and for the Carousel visit: https://stackoverflow.com/questions/19469705/bootstrap-carousel-as-website-background