When you use the word biological, you're talking about life and living things. You'll recognize the root "bio-," meaning "life," as in biography — the story of someone's life — and biology — the study of living organisms.
The woman who gave birth to you is your biological mother — she's passed her genes on to you and you're related to her, even if somebody else raised you. Anybody you share genes with is your biological relative. Biological cleaning products make use of natural enzymes, and they're supposed to be safe and non-toxic. On the other hand, biological warfare uses bacteria, viruses, and other naturally occurring poisons to injure and kill people.
