Engineering simulations are computer-based models that replicate real-world physical systems to predict their behavior under various conditions. These simulations help engineers analyze how designs will perform, allowing them to identify potential issues before actual production. By using finite element analysis (FEA) or computational fluid dynamics (CFD), engineers can visualize stress, heat transfer, and fluid flow in their designs. This process saves time and resources, as it reduces the need for extensive physical prototypes and testing, ultimately leading to more efficient and effective engineering solutions.