Bilateral symmetry is when an animal's body can be divided into mirror-image halves along a single plane. Most animals, including humans, exhibit bilateral symmetry.

The Animal Kingdom is classified based on characteristics such as body symmetry, presence or absence of a coelom, segmentation, and the structure of various organ systems. Major groups include invertebrates (e.g., sponges, cnidarians, arthropods, and molluscs) and vertebrates (e.g., fish, amphibians, reptiles, birds, mammals).

The nervous system coordinates and regulates bodily functions, responds to environmental stimuli, and enables communication between various body parts.