The term "all" refers to the totality of a group or category, encompassing every individual or element within it. It signifies completeness and inclusivity, indicating that nothing is excluded. For example, when we say "all animals," we mean every species, from cats to elephants. In mathematics, "all" can represent a universal set, which includes every member of a particular domain. In logic, it is often used in statements like "all humans are mortal," meaning that every member of the human species shares the characteristic of mortality.