Xeno, short for "xenobiology," refers to the study of extraterrestrial life forms, often depicted as aliens. These beings are imagined to exist beyond Earth and can vary widely in appearance, behavior, and biology. The concept of xenos has been popularized in science fiction, where they are often portrayed as intelligent species with advanced technologies. In scientific discussions, xenos are considered in the context of astrobiology, which explores the potential for life on other planets. Researchers examine extreme environments on Earth, such as deep-sea vents and Antarctic ice, to understand how life might survive in harsh conditions elsewhere in the universe.