One of the major advantages of an automatic egg incubator is that it turns the eggs for you, so you don’t have to. The eggs sit in compartments on a specially designed tray. The tray is turned automatically by a motor which causes the eggs to rotate.
If you want to be more involved in the incubation process, then a manual egg incubator is for you because with a manual egg incubator, you are required to turn the eggs at least three times a day by hand. It is best that you mark one side of the eggs so that you can track when they were last turned. It is important that eggs are turned regularly as the chick can stick to the inside of the shell.