"Anaerobic" refers to processes that occur without the presence of oxygen. This term is often used in biology to describe certain types of organisms, like anaerobic bacteria, which thrive in environments devoid of oxygen. These bacteria play a crucial role in breaking down organic matter, contributing to processes like fermentation and decomposition. In addition to bacteria, anaerobic conditions are important in various applications, such as wastewater treatment and biogas production. In these settings, organic waste is broken down by anaerobic microorganisms, producing valuable byproducts like methane, which can be used as a renewable energy source.