Difference Equations Definition/Meaning:
Equations that have the same general form as recurrence relations; however, the term also refers to situations in which the solution is
not determined recursively from initial conditions. Difference equations play a
large part in numerical computation. The equations are sometimes expressed in
terms of differences of function values rather than function values themselves.
The standard difference representations are:
Dƒ(x) = ƒ(x + h) -
Ñƒ(x) = ƒ(x) -
ƒ (x - h)
¶ƒ(x) = ƒ(x + 1/2h) - ƒ(x - 1/2h)
Difference equations arise in the application of the finite difference method.