Aerobes are organisms that require oxygen to survive and grow. They use oxygen in their metabolic processes to produce energy, which is essential for their cellular functions. Common examples of aerobes include many types of bacteria, fungi, and animals, including humans. There are two main types of aerobes: obligate aerobes, which must have oxygen to live, and facultative aerobes, which can grow with or without oxygen. Obligate aerobes rely entirely on aerobic respiration, while facultative aerobes can switch to anaerobic processes when oxygen is scarce. Understanding aerobes is important in fields like microbiology and medicine.