Have you seen that phrase, "separate eggs" and found yourself having a hard time breathing?! I HAVE! If I see "separate eggs" or "one egg yolk" SKIP! I don't like having to do this. However, separating eggs isn't that hard and you do use both parts of the egg normally but just at different times when making a cake. 

The egg whites are used to make meringue. I am not a fan of meringue on top of a pie but inside a cake - OOOOH YEA! Adding the meringue inside the cake batter makes it light and moist. Not every cake calls for this though, so look through the directions before making your cake.

In the video, I just use the eggshells to help me separate them but there are tools you can use instead if you prefer that.