In this paper, plant-based will be used as an umbrella term for those diets which abstain from some or all animal by-products (such as veganism and vegetarianism). Veganism is the elimination of all animal by-products from consumption and vegetarianism is the elimination of all meat (including fish) from the diet with the inclusion of dairy and eggs. A pescatarian is one who abstains from all meat except for fish.
Factory farming is used to describe intensive industrialized animal agriculture, or animal husbandry in which very dense quantities of animals are raised for sale. It is a large operation that raises massive numbers of animals for food; they hold large numbers of animals, typically cows, pigs, turkeys, or chickens, often indoors at high densities. The goal and focus of the operation is to produce large quantities of meat, eggs, or milk at the lowest possible cost.