Interaction design is an important component within the giant umbrella of user experience (UX) design. It can be understood in simple (but not simplified) terms: it is the design of the interaction between users and products. Most often when people talk about interaction design, the products tend to be software products like apps or websites. The goal of interaction design is to create products that enable the user to achieve their objective(s) in the best way possible. Interaction design, often abbreviated as IxD, is “the practice of designing interactive digital products, environments, systems, and services.” Beyond the digital aspect, interaction design is also useful when creating physical products, exploring how a user might interact with it.
UX design is about shaping the experience of using a product, and most part of that experience involves some interaction between the user and the product. But UX design is more than interaction design: it also involves user research (finding out who the users are in the first place), creating user personas (why, and under what conditions, would they use the product), performing user testing and usability testing, etc.