A surface plot visualizes a two dimensional, single patch using different fill colors for each patch segment. Each patch segment is a (pseudo) rectangle, that means input data is given in form of a data matrix.
We can distinguish between the outer side and the interior parts of a surface by choosing different colors.
The code is from the PGFPlots 1.10 manual: “4.6.6 Surface Plots”.
\documentclass[border=10pt]{standalone}
\usepackage{pgfplots}
\pgfplotsset{width=7cm,compat=1.8}
\begin{document}
\begin{tikzpicture}
\begin{axis}[
axis lines=center,
axis on top,
xlabel={$x$}, ylabel={$y$}, zlabel={$z$},
domain=0:1,
y domain=0:2*pi,
xmin=-1.5, xmax=1.5,
ymin=-1.5, ymax=1.5, zmin=0.0,
mesh/interior colormap=
{blueblack}{color=(black) color=(blue)},
colormap/blackwhite,
samples=10,
samples y=40,
z buffer=sort,
]
\addplot3[surf]
({x*cos(deg(y))},{x*sin(deg(y))},{x});
\end{axis}
\end{tikzpicture}
\end{document}