> OpenAI Codex was trained on publicly available source code and natural language, so it works for both programming and human languages. The GitHub Copilot extension sends your comments and code to the GitHub Copilot service, and it relies on context, as described in Privacy below - i.e., file content both in the file you are editing, as well as neighboring or related files within a project. It may also collect the URLs of repositories or file paths to identify relevant context. The comments and code along with context are then used by OpenAI Codex to synthesize and suggest individual lines and whole functions.

"How Does Copilot Work"