Procedural generation versus random generation

I'd like to make a distinction before we go any further. In this book, we're going to talk a lot about procedural generation and random generation. These terms are often used interchangeably, but they are not the same thing. Therefore, let's take a moment to define them.

Procedural generation

Procedural generation is the process of creating content using an algorithm. This in itself has no element of randomness. If the functions, expressions, algorithms, and inputs that are used to generate the content remain the same, then you'll always get the same results. This is due to the fact that computers are deterministic, which is something that we'll cover shortly. Procedural generation is not inherently random.

Random generation

Randomness is induced when we give these algorithms different inputs or alter their expressions. This variance is what creates the variety of the output. When someone says something was procedurally generated, they usually mean procedurally generated utilizing randomness.