Meringue is a special mixture that people use to make sweet treats like pies or cookies. It's made from just a few ingredients: egg whites (the clear part of an egg), sugar (a sweet powder), and sometimes cream of tartar (a special powder that helps the egg whites get really fluffy).
When you make meringue, first you whisk the egg whites really hard until they turn white and frothy. Then you add some sugar a little bit at a time while you keep whisking. The mixture will start to feel sticky and glossy as the sugar dissolves into the egg whites.
Once you've added all the sugar, you keep whisking for a few more minutes until the mixture gets really stiff and shiny. Sometimes, you can add flavors to the meringue like vanilla extract or a little bit of lemon juice.
After you've made your meringue, you can use it to top pies like Lemon Meringue Pie, or shape it into little round cookies before baking them in the oven. The best part about meringue is that it gets really light and delicate, with a slightly crispy outside and a soft, marshmallowy inside that melts in your mouth.