Instructional software simulations are computer programs that model real-world systems to allow predictive experimentation without risk. They are used across various academic and industrial fields for applications like business, health, manufacturing, and more. Simulations are selected based on ease of use, accessibility, features, and cost. They have advantages like being engaging and promoting critical thinking, but also have disadvantages like preparation time and complex assessment. Simulations can be used in practice and presentation modes to both teach concepts and allow practice applying knowledge. Guidelines for effective use include ensuring student understanding, anticipating questions, monitoring progress, and establishing learning goals.