I suppose it's a combination of both. They can't possibly enter them all manually (even if they are very speedy typers) and no algorithm can reproduce all reasonable variants without producing a lot of trash either.
As to the use of the word algorithm: it's a fancy way of saying "detailed cooking recipe": a set of precisely defined steps that transform some input (a bunch of ingredients) to a desired output (a tasty cake).
That makes sense. And thanks for the definition of algorithm. I thought of it as a kind of auto-generated means of selecting stuff according to some established criteria and mixing them up according to some established method, resulting in an unpredictable mess. But then, I may be a bit cynical. Or too wed to the humanities.