Processes may consistently produce the same result when given the same input
and context. These deterministic processes are what most people mean when they
refer to a process in an unqualified manner. Given the same input, two identical
probabilistic processes may produce different results. The output of a probabilistic
process may be described by a probabilistic distribution or density function.
Observers of such a process may understand the randomness as coming from two
sources: inherently random processes and error-producing noise.