# Core concepts

The terms used across these docs, and how the app, the CLI and AI agents share one vault.

This page defines the terms used across the docs. It also shows how the app, the CLI and an AI agent work on the same vault.

## Terms

| Term | What it means |
| --- | --- |
| Vault | A folder that Loam opens. Notes, settings, plugins and deleted items live in it. |
| Note | A `.md` file in the vault: Markdown text, with optional properties at the top. |
| Property | A `key: value` line in the YAML frontmatter, between two `---` lines at the top of a note. |
| Tag | A word such as `#project` in the text, or an entry in a `tags:` property. |
| Link | A link from one note to another, such as `[Plan](Projects/Plan.md)`. |
| Command | An action with an id such as `daily.append`. The app and the CLI both run commands. |
| Plugin | A feature. Even the editor is a plugin, and you turn each one on or off. |
| Collection | A `.base` file that shows a folder of notes as a table, a board or a gallery. |

## One vault, three ways in

The app, the `loam` command line and your AI agent read and write the same files. A change made in one shows in the others. The app watches the vault folder, so a note written by a command or an agent appears at once in the open window.

Most actions are commands too, so anything you do in the app can also run from a terminal or from an agent. `loam app info` shows which vault the running app has open.

## Plugins

Plugins add features to a small base app. The features of Loam are plugins too, built the same way as yours. A plugin you add from someone else stays off until you enable it, so read its permissions first.

A plugin declares what it can touch, such as reading or writing the vault, the network or the clipboard. Its own data is plain Markdown in the vault.

## Plain files

Everything is a plain file: Markdown notes, `.base` collections, `.canvas` boards and Excalidraw drawings. Nothing is kept in a proprietary format or a hidden database.

> **Tip:** For AI agents: `loam guide` lists the topics. `loam guide notes` explains how notes, tasks and collections are written.