When you go to the supermarket to buy eggs, you are faced with a variety of different sizes and colors. The shape, well, that is generally the same. You think of what you will make with them, as far as recipes, to decide whether to purchase medium sized or large ones. Maybe you will need the jumbo size.
You rarely think of what the farmer and the chicken went through to get them. Well, if you have ever seen the little chicks they sell at certain times in the spring, you can see what happens when they are fertilized. If you want them, all you have to do is to buy a chicken. If you want more chickens, you need to buy a rooster.
So the chicks are brought home to the farm, and they are set up in a very warm environment. The more the farmer buys, the warmer they will keep each other. A bright light needs to be on them all the time at this point, and they will eat a lot of chick feed. As they grow, they become the age to lay eggs. Different types of chickens lay different eggs.