# What is the meaning of the symbol $C^\infty$?

What is the meaning of the symbol $C^\infty$ (often used in defining a smooth functions)? I'm a student of physics, and my knowledge of mathematical symbols is sloppy.

Is the set of functions with infinite continuous derivatives, that is $C^\infty(A,B)$ is the set of functions from $A$ to $B$ that have infinite continuous derivatives.