# Operators Operators are special kinds of functions. They take a *function* as input, and return a *function* as an output. A few examples are: * Derivative * [Laplace-Transform](Laplace-Transform.md) (integral operator) * [Divergence](Divergence.md) * [Gradient](Gradient.md) * [Curl](Curl.md) ### Linear Operator The derivative is a type of linear transformation, known as a *linear operator*. See the whiteboard photos [here](https://photos.google.com/photo/AF1QipMhmuP2QBHWmA5QbooQLUUFe8RtjDbOHO5SHs0h). Also, see how this comes about from the concept of [Abstract Vector Spaces](Abstract%20Vector%20Spaces.md). --- References: * https://www.youtube.com/watch?v=TgKwz5Ikpc8&list=PL0-GT3co4r2y2YErbmuJw2L5tW4Ew2O5B&index=15&t=521s * https://math.stackexchange.com/questions/204221/what-is-an-operator * https://en.wikipedia.org/wiki/Operator_(mathematics)#Calculus