Continuous Distribution of Charges--

When we consider the charged body of reasonable size, charge has continuous distribution. The continuous distribution of charge may be of one dimensional, two or three dimensional.

Linear Charge Density--

When charge is distributed along a line, the distribution is called linear.

If Charge q is distributed over the length L, then 

Linear charge density(λ) =q/l

Surface Charge Density--

When charge is distributed over the entire surface, the

distribution is called Surface charge distribution. If

Charge q is distributed over the area A, then 

Surface charge density( =q/A

Volume Charge Density--

When charge is distributed over the entire volume of the

 body, the distribution is called Volume charge distribution.

If Charge q is distributed over the volume V, then 

Volume charge density(ρ) =q/V