1. What is Claude Code?

Notes

What is Claude Code? Claude Code is an agentic coding tool that understands your codebase, edits your files, runs commands, and integrates with your existing developer tools to help you get things done faster. It is available in your terminal, Visual Studio Code, the Claude Desktop app, on the web, and in JetBrains IDEs.

What Separates Claude Code from Claude? Unlike Claude.ai, Claude Code doesn't copy and paste code back and forth — it goes in and does the work itself. The key differentiator is that Claude Code works as an AI Agent.

What is an Agent? An AI Agent is software that can interact with its environment and perform actions to complete a defined goal. At its core, this works by having a large language model operating in a loop in real time. AI Agents can have access to tools, external services, or even other AI Agents to help reach their goals.

What Can Claude Code Actually Do?

Read and understand your codebase — explain a feature or trace a bug throughout your code
Edit files across your project
Run terminal commands — execute your build script, run tests, install packages, and use the output to decide what to do next
Search the web — look up documentation or the latest API references

Using Claude Code Effectively — three concepts to keep in mind:

The context window — Claude's working memory. It can hold a lot but not everything at once. Claude finds strategic ways to locate answers within your codebase without loading the entire thing.
It asks for permission — by default, Claude will ask before running commands or making changes. You're always in control.
It can make mistakes — staying in the loop helps you catch errors early.

Recap: Claude Code is an agentic coding tool. It reads your codebase, edits your files, runs commands, and connects to external tools to help you ship faster.