This document defines simulations as computerized models that represent real or imagined systems in order to teach how those systems work. Simulations create environments resembling real life to allow students to practice and gain experience without risk. There are different types of simulations including exercises, games, and role playing. Simulations are used in nursing education and can involve simple models, standardized patients, computer-based clinical scenarios, high-tech procedural equipment, and virtual reality. Teachers plan, facilitate, and debrief simulations. Advantages include combining theory and practice, active participation, safety, evaluation, and motivation. Disadvantages include not all subjects can use simulations, complexity for young learners, reduced seriousness, expense, and time consumption.