A drawer in a filing cabinet. Documents go inside. You can label it, put drawers inside drawers, and anyone with access to the cabinet sees the same documents.
A folder (programmers say “directory”) is exactly that on your computer. A file is one document: a spreadsheet, a contract, a photo, a note. Folders hold files and other folders. Every file has one address, its path, such as Documents/Clients/Acme/contract-2026.docx.
The one idea worth repeating until it is boring: a folder does not belong to a program. Windows Explorer shows it as icons. VS Code shows it as a tree. Claude Code reads it and writes into it. Open the same folder in all three and create a file in one; it appears in the others immediately, because there is only one folder.
When you point an agent at a folder, that folder becomes its project. Everything it needs should be inside, and everything it produces lands inside. That is the file-first way of working.
Example
Create a folder called ai-school-homework. Put three files in it: a short text note, a spreadsheet, a PDF. Open the folder in Explorer, then in VS Code, then start Claude Code inside it. Ask “what is in this folder?”. Same three files, three windows.
Why it matters for you
Files persist; conversations do not. Anything you want the agent to know next week belongs in a file in the project folder, not in a chat. Anything you want a colleague to reuse belongs there too. Get the folder right and most of the rest of the course becomes easy.
Related
- Project - a folder with an agent pointed at it
- Context window - why files, not chat, are your real memory
- Mental models - files first