What is Codex primarily focused on?

Codex is OpenAI's coding tool, and the word doing the work is coding: it reads a real repository, edits files inside it, and runs the commands you already have installed. That is a different job from a chat window that returns a snippet. The unit of work is a change to your project, not a paragraph you paste somewhere.

It appears in three places doing the same job from different angles — a terminal client, an extension inside your editor, and a cloud version that runs a task in its own isolated environment. Which one you reach for is a question about where you already work, not about what the tool can do.

The three wrong answers are worth noticing because each names something OpenAI genuinely sells: image and video generation, and real-time speech and transcription. None of them is this product. That is the distinction to hold on to — a vendor's model catalogue is broad, and the individual tools built on it are narrow. Codex is the narrow one, pointed at software.