Room temperature is what most of your ingredients should be at before you use them. This can help considerably when you're trying to beat egg whites, or make a cake or bake bread.

Milks and other liquids added to batters, soups or sauces should be brought to room temperature before you begin the recipe, or they can be heated briefly at a low setting in the microwave or in a pan of warm water. (Heating them directly takes longer and may scorch them.)

Meats that are at room temperature cook faster and some meats can be more tender if the fat has had time to de-solidify.