Interaction Design or “IxD,” falls somewhere within the giant purview of UI/UX. There is a lot of overlap between this and product design, and also general visual/UI design. When we talk about interaction, we’re mostly interested in interfaces, cues, actions and reactions. Oftentimes this means exploring interfaces and interactions with a focus on the various states of an interface, including hover and click states, and also the animations or transitions from one state to another.
There is a lot of detail and nuance that goes into designing interactions, and as such it is critical to prototype and test everything before it goes into development. Luckily, we have fantastic tools such as InVision Studio and Anima for designing interactions and animating elements of an app or website.