In Vitro Models are experimental systems that allow scientists to study biological processes outside of a living organism. These models typically involve cells or tissues cultured in a controlled environment, such as a petri dish or test tube. By using cell lines or primary cells, researchers can investigate cellular functions, drug responses, and disease mechanisms in a simplified setting. These models are essential for various fields, including pharmacology, toxicology, and cancer research. They provide valuable insights while reducing the need for animal testing. However, it's important to note that results from in vitro studies may not always fully replicate the complexities of living organisms.