Contextual inquiry is a user research method that is helpful to define requirements, improve processes, learn what's important to users, and spark ideas for future projects.
Contextual inquiry is a UX research method where you shadow people as they do their job (or leisure tasks), allowing you to ask questions in context. This video provides advice on overcoming the main challenges with this method.
Good UX design requires understanding the context and patterns of human behavior, especially in new products or features that solve real needs. The 5 steps to rapid corporate ethnography lead you to these discoveries.
In a museum, knowing the backstory of an artifact makes it more interesting. Similarly, in a UX project, you can make better decisions when you know the context of your UX artifacts like journey maps and wireframes.