The study of mechanical interaction of structures at their surfaces is essential in many applications. An accurate understanding of stress and deformation arising from contact is critical for the design of reliable, efficient and safe products such as disc brakes, gears and tires. However, unlike the real world, bodies do not automatically interact with each other in numerical simulations. In order to model those interactions, proper contact definition between the bodies is required. In this course, we understand how contact is modeled in numerical simulations and demonstrate the use of Ansys Mechanical software in modeling contact.