The principles of cooking eggs in the shell are applicable to poached eggs. The only difference between the two items is the shell.
This difference, of course, complicates the cooking process, as emphasized in the following procedure. The object is to keep the eggs egg-shaped—that is, in a round, compact mass rather than spread all over the pan.
Other liquids besides water can be used to poach eggs to create a variety of flavor combinations. In the Mediterranean/North African dish shakshuka, eggs are poached and served in a spiced tomato sauce.