Mix
No surprises here—mixing refers to stirring two ingredients together until they are evenly combined.
Beat
Beating means combining ingredients and then adding air using a whisk, fork, spoon, or electric mixer until the mixture is smooth.1
Whisk
Whisks, as you have already learned in the Kitchen Utensils section, are common kitchen tools consisting of a long handle and wire or plastic loops at the other end. To whisk something means to use a whisk to beat ingredients together.2
Whip
Whipping refers to beating an ingredient or mixture, such as heavy cream or egg whites, to incorporate air and thus increase volume and lightness. When whipping cream or egg whites, soft, firm, and stiff "peaks" form depending on how long you have been whipping them.1
Fold
Folding is a technique for adding a light ingredient or mixture to a heavier mixture without losing the airiness. It often comes up when making a souffle, mousse, or angel food cake. Typically, you should add the light ingredient/mixture to the heavier mixture. Next, run a spoon or spatula down the middle of the mixture. Once you reach the bottom of the bowl, rotate the spatula or spoon to bring some of the heavy mixture at the bottom of the bowl back to the top. The folding occurs when you rotate the spatula or spoon once more to put some of the heavier mixture on top of the lighter mixture. You should rotate the bowl and repeat these steps until the ingredients are evenly distributed.3
Bind
Binding refers to getting ingredients to stick together so your meatballs, veggie burgers, homemade granola bars, muffins, etc. do not crumble or fall apart. Eggs are often used for binding, though some recipes will work with banana, avocado, nut butter, flax seed, etc. Binding may also refer to adding egg yolk, flour, or starch to make a sauce smooth, thick, and uniform (see thickening).4
Leaven
Leavening is the creation of bubbles of air or carbon dioxide to make baked goods rise. Common leavening agents include yeast, baking powder, baking soda, and eggs.5
Recommended Read

How to Cook Everything
If you are teaching yourself how to cook, this guide is a must have reference book.
check it out ยป