TLDR: a multidisciplinary engineering field that combines software, electrical and computer, and mechanical engineering.
Sometimes referred as robotics, mechatronics is the most promising discipline in the engineering world. The brightest students are competing to enter this program for it's reputation and employment rate by the top notch companies in the industry(Microsoft, Google, Apple, Tesla etc). University of Waterloo is known as the best university offering this program. Rumor has it that they are the ones came up with this concept and terminology back in the day.
Person 1: Dude, I got accepted into Mechatronics Engineering.
Person 2: The hell is mechatronics?
Person 1: Story short, we're going to build robots!