Quick answer: The OG AI-pair programmer — autocomplete + chat in your IDE.
GitHub Copilot is an AI-powered code completion tool developed by GitHub and Microsoft, built on large language models trained on public code repositories. It functions as an AI pair programmer that integrates directly into your IDE, offering two primary features: inline code autocomplete that suggests entire functions or code blocks as you type, and a chat interface for asking questions and getting coding help without leaving your editor. Available for VS Code, JetBrains IDEs, Vim, and other popular environments, Copilot accelerates development by reducing boilerplate coding, suggesting implementations based on context and comments, and helping debug issues. At $10 per month for individual developers, it's the most established AI coding assistant on the market, having set the standard for IDE-integrated AI assistance since its launch.