What is the air in the egg for?

The air position in an egg is called an air chamber.

The purpose of the air chamber is to keep the air, which is very important in the incubation process. When fertilized eggs hatch, the egg white will gradually peel off the eggshell, and the air chamber can exchange air inside and outside.

If the egg is full, it won't hatch. Young birds need to breathe during their development, and the air chamber undertakes the air exchange channel.