Interaction design means different things whether it relates to video games or user interfaces. In this major, we focus on the design of user interfaces including mobile apps, websites, software interfaces, and kiosks.
But what exactly does focusing on "interaction" as a designer mean? Usability.gov defines interaction design as creating engaging interfaces with well thought out behaviors. This makes interaction design somewhat different from more traditional forms of design, like graphic design. According to Alan Cooper, a chief proponent of interaction design, a focus on behavior design in complex systems is what sets interaction design apart.
This means that interaction designers will help guide product development from the opening to the final stages. This could mean working on a team that is creating a mobile app or the touchscreen in a car. During the design process, interaction designers will speak to clients, stakeholders, developers, visual designers, and, most importantly, to users. Interaction designers will always ask the question, "Will this decision make the experience of this product better for the user?"
In their focus on users, interaction designers use prototyping tools to create prototypes for clients and user testing situations.
Interaction design, as Alan Cooper says, borrows theories and techniques from traditional graphic design, usability, engineering, and human-centered disciplines like anthropology and psychology. This means that interaction design is not limited to one of these skill sets and blends all of these approaches in the service of user experience.