Two main representations for surfaces

Explicit representation

\[S(u,v)=(x(u,v),\,y(u,v),\,z(u,v))\]
Parametric map
explicit.svg
+ Neighborhood information

Implicit representation

\[S=\{(x,y,z)\in\mathbb{R}^3 \; |\, F(x,y,z) = 0\}\]
Isosurface of scalar field
implicit.png
+ Topological modification