The more you cook, the more you'll run into recipes that call for just egg whites. You may a few questions about egg whites and fortunately they're almost all easy to answer. Egg whites are simple to separate and once you practice a few times, you'll have it down in no time. Here are some instructions to get you started!
First and foremost, an egg white is the part of the egg that's not the yellow yolk; it's that clear, kind of goopy stuff surrounding the yolk. When you separate egg whites, you separate the white from the yellow and it's really easy to do.
Crack the egg and when you do make sure the break is on the cleaner side (having it be too cracked and falling apart won't work for separating egg whites). Once the egg is cracked take both halves of the egg and hold them upright (make sure that yolk doesn't break, otherwise it won't work).
Then over whatever container you're using for the egg whites, slowly and carefully transfer the egg yolk back and forth between the two halves of the shell. As you transfer the yolk back and forth, the white of the egg will fall out into the bowl or container below.
As you're doing this just be aware of the yolk and make sure it doesn't break or mix with the newly separated white. If it does, then the white won't do what it's intended to do when you cook with it.
Once you're finished separating the egg white from the egg yolk, then you can just throw away the yolk and the shell, unless you're using the yolk for another recipe. Many different recipes require egg yolks—usually frostings or candies.
Now that you know how to separate the egg whites from the egg yolks you're definitely in a good position to advance your cooking skills. Probably the first couple of times you'll need to practice to make sure you have it down, but after a few attempts you should be ready to roll!