Definition
Plain language
The clickable, windowed interface most computer programs show their users.
As stated in the literature
Graphical User Interface — the visual, pointer-driven interaction surface of an application, distinct from CLI; the target of computer-use agents like Browser-Use and ToolCUA.
Why it matters: Most software in the world only has a GUI, so agents that can drive them open up automation for tasks that don't expose APIs.
For example, a computer-use agent has to click the right button in a desktop app's GUI, which means it needs to actually see and interpret the screen.
Heard on the show
“And here's why this matters even if you don't follow GUI agents at all.”Episode 189 — Why Phone Agents Ace the Test and Crash on Your Actual Phone