\begin{definition}[Definition:Generating Curve of Surface of Revolution]
Let $H = \set {\tuple {x, y} : y \in \R_{> 0}} \subset \R^2$ be the open upper half-plane.
Let $F \subset H$ be a $1$-dimensional embedded submanifold.
Let $S_F$ be a surface of revolution.
Then $F$ is called the '''generating curve''' of $S_F$.
\end{definition}