Whats is IAB (Integrated Access Backhaul) in 5G?

Hello Experts,
Regarding new IAB (Integrated Access Backhaul) in 5G, does anyone has some explanation with pros and cons?
Whats is the relation with Fronthaul, Midhaul and Backhaul?

IAB means using part of Access Spectrum as Backhaul.

Hello @marcelofb, You can chech my article here:

Rel-17 telling that BW sharing between RAN and Backhaul is flexible.