What does level mean in cooking?

Leveling and Smoothing: In baking and pastry, leveling and smoothing are often interchangeable terms. They refer to the process of making sure the surface of a cake, pie, or other dessert is even and smooth before baking. This is usually done with a spatula or an offset spatula.

By leveling and smoothing the surface, you can help ensure that the dessert will bake evenly and have a professional appearance.