GitHub Copilot Chat is a conversational interface designed to assist developers within their IDE. Its primary function for understanding an existing codebase is its ability to process natural language queries. Developers can highlight a block of code and ask questions like "What does this code do?" or use slash commands such as /explain. Copilot Chat then analyzes the selected code in context and generates a detailed, human-readable explanation, clarifying its purpose, logic, and functionality. This direct, interactive question-and-answer capability is a core feature for accelerating code comprehension.

A. Running linters and formatters is a function of separate IDE extensions or built-in tooling for maintaining code style and quality, not a primary feature of GitHub Copilot Chat.

B. GitHub Copilot Chat is a text-based large language model; it does not natively generate visual outputs like UML diagrams or code structure graphs within the chat interface.

D. While Copilot Chat can suggest refactoring based on a user's prompt (e.g., "refactor this for clarity"), it does not perform this automatically. Its core contribution to understanding is through explanation, not modification.

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1. GitHub Docs, "Using GitHub Copilot Chat in your IDE." This official documentation explicitly details the feature of asking questions to understand code. It states, "You can ask Copilot Chat to help you by... explaining a selected code snippet." It also describes the /explain slash command, which is "used to get an explanation of the selected code."

Reference Location: Section "Asking questions about your code."

2. GitHub Docs, "Getting started with GitHub Copilot." This guide introduces the core capabilities, including the chat interface's role in code comprehension. It highlights that Copilot can "explain and document code" by generating summaries of a file's purpose or explaining a selected code block.

Reference Location: Section "See suggestions from GitHub Copilot Chat in your editor."

3. Li, Z., et al. (2023). How do software developers use AI-powered code assistants? An exploratory study of GitHub Copilot. Proceedings of the 45th International Conference on Software Engineering (ICSE '23). This peer-reviewed study analyzes how developers use Copilot. The findings show that a significant use case is "Code Explanation," where developers use the tool to understand unfamiliar or complex code segments, confirming that this is a key real-world application.

Reference Location: Section 4.2.1 "Code Explanation."

DOI: https://doi.org/10.1109/ICSE48619.2023.00071