In plain English
Lots of apps and websites have no easy way for software to connect to them. Computer use gets around that. The AI looks at the screen and uses the mouse and keyboard, so it can work in almost any app.
Example
An AI agent fills in expense reports by opening the company's old expense website, typing in each receipt and clicking submit, just like an employee would.
In short
Mouse and keyboard included. AI that clicks and types on a screen like you do.
Why it matters
Computer use lets AI agents work with older software and websites that have no API. It's still slower and less reliable than a direct connection, and it raises security questions, so it usually runs in a sandbox with limits.
Common confusion
Computer use vs. tool calling. Tool calling connects an AI straight to software through an API, which is fast and precise. Computer use goes through the screen like a person, which is slower but works almost anywhere.