This system's brilliance comes from the sheer infinite number of worlds that are possible, but also allows you to save an awesome seed should you happen to stumble upon one and to share it with others.
When each world is generated, it will randomly assign a seed to that world, however, it is possible to manually assign a seed to a world by typing in a series of numbers or sometimes words.
How Minecraft does this is through is a system referred to as seeds. Minecraft is known for generating infinite worlds with infinite possibilities of how these worlds actually look.
