Often times recipes call for beaten eggs, or for you to beat the eggs, before adding them to a batter.
Beating the eggs before adding them to the batter is very important. This step is often skipped though because many people think it is a waste of time. They just crack the eggs right into the batter and go about mixing.
I want to encourage you though not to skip the step of beating the eggs when a recipe calls for it. Many batters, like pancakes and muffins, can be over mixed. And if they are over mixed the end result will not be as good.
If you add in the eggs whole, it will require you to mix the batter more to incorporate the eggs in and break them up. But if you beat the eggs before adding them to the batter, it will not take very much time at all to mix them in, and you will be less likely to over beat the batter you are making.
So, when a recipe calls for beaten eggs, I encourage you to not skip the step of beating them. It really will make a difference in the end result.