What's the difference between Area Density and Linear Density?

[Zyos]

Homework Statement

It's for our termpaper thing and i can't get any reliable sources on the net, so might get a shot at asking it here, What are the Differences between Area and Linear Density?

Homework Equations

The Attempt at a Solution

 

[cepheid]

Area density is the mass per unit area, and linear density is the mass per unit length. The former applies in a 2D situation, and the latter in a 1D situation.