GitHub Copilot Enterprise is the only plan designed to be tailored to an organization's specific environment. It includes the capability to index an organization's private repositories, creating a custom knowledge base. This allows GitHub Copilot to provide more relevant, context-aware code suggestions and answers to natural language questions about the company's internal codebase. This feature is a key differentiator of the Enterprise plan and is not available in the Individual or Business tiers, which rely on the general model trained on public code.

A. GitHub Copilot Individual: This plan is for personal use and does not have access to any organization-specific codebases or knowledge bases.

B. GitHub Copilot Business: This plan offers organization-wide policy management and security features but does not include the capability to index and learn from a company's private repositories.

D. GitHub Copilot Professional: This is not an official name for a GitHub Copilot pricing plan. The official tiers are Individual, Business, and Enterprise.

1. GitHub Docs, "About GitHub Copilot Enterprise." This official documentation states, "With a subscription to GitHub Copilot Enterprise, your organization can give developers access to a powerful AI assistant that is tailored to your organization's code... Copilot can answer questions about your codebase, and help you navigate your codebase." This directly confirms the feature is part of the Enterprise plan.

Source: GitHub Docs, "About GitHub Copilot Enterprise," Accessed October 2023.

2. GitHub Resources, "Comparing GitHub Copilot Business and GitHub Copilot Enterprise." This comparison table explicitly lists "Personalization: Copilot is customized on your organization's codebase" as a feature exclusive to GitHub Copilot Enterprise.

Source: GitHub Resources, "Comparing GitHub Copilot Business and GitHub Copilot Enterprise," Section: "Feature comparison."

3. GitHub Blog, "GitHub Copilot Enterprise is now generally available." (February 2, 2024). The announcement highlights, "Copilot Enterprise is customized to your organization’s codebase... It weaves the context of your company’s knowledge and internal codebase into every developer’s workflow through two new, key capabilities: deep-dive understanding of your codebase [and] instant answers about your codebase."

Source: The GitHub Blog, "GitHub Copilot Enterprise is now generally available," Paragraph 2.