Mechatronics is the combination of a mechanical system, a computer, a control system, and an electrical system. This is also known as an embedded system.
An electric door lock, which can be a keyless door lock, is an example of implementing mechatronics.
Mechatronics is a branch of engineering that has emerged with the combination of Mechanical engineering, Electrical engineering, and Software engineering.
Mechatronics greatly deals with robotics, as robotics is based upon mechanical, electrical and software system.