Insight
A non-obvious observation about people, usually surfaced through research, that changes how you think about a problem.
Persona
A composite portrait of a kind of person you're designing for — built from real research, not from imagination.
Journey
The sequence of steps, feelings, and friction a person moves through when trying to achieve a goal.
Prototype
The cheapest possible version of an idea that can answer a specific question.
Synthesis
The act of turning raw research notes into themes, patterns, and decisions the team can act on.