Model organisms are non-human species that are extensively studied to understand biological processes. They are chosen for their specific traits, such as rapid reproduction, genetic similarity to humans, or ease of manipulation in a laboratory setting. Common examples include fruit flies, mice, and zebrafish. Researchers use model organisms to investigate various aspects of biology, including genetics, development, and disease mechanisms. Findings from these studies often provide insights that can be applied to human health and medicine, making model organisms essential tools in scientific research.