We examine several properties of the diffusion equation and its solution. The basic diffusion equation is:
where 
, 
, 
, and c>0 is constant.
Note in particular that the region of n-dimensional space 
where
we seek a solution may be bounded or infinite. The parameter c is
sometimes referred to as the conduction coefficient. The operator 
is called the Laplacian. The solution to the partial differential equation (2.1) is
not unique, but a unique solution may be obtained if we imposed certain boundary conditions.
