A "byproduct" is something that is made or produced as a result of a different process or action. It is not the main goal or focus, but rather an extra or unintended outcome. Full definition
Thinking about it in that way, characters are sort of byproducts of that process. (gonintendo.com)
As described in the author's previous book Grain Brain, the two key mechanisms that lead to brain degeneration are chronic inflammation and the action of free radicals, which for now you can think of as byproducts of inflammation that cause the body to «rust.» (chewfo.com)
These are made out of byproducts from industries such as the corn industry and have less chemicals in them to irritate baby's skin. (best-baby-gift-ideas.com)