# Concepts

What Rack Maker's words mean - racks, mounts, devices, projects, revisions, namespaces, access, and licences.

Source: https://rack-maker.cbnsndwch.dev/docs/getting-started/concepts

## Racks

The frame everything goes in: an open-frame 10″ or 19″ rack, a DeskPi RackMate, or wire shelving. Its rails, or its shelves, give the places things can go, counted in U (rack units). The RackMate T0 counts in half-U.

A rack is a catalog entry like any other part, so new kinds of rack can be added to the [catalog](https://rack-maker.cbnsndwch.dev/docs/catalog) without changes to the app.

## Mounts

What attaches to the rails: shelves, trays, cradles and brackets, bought or printed. Each takes a number of positions, and devices sit on them. Printed mounts come with STL files, listed under **Printed parts**. See [Exports and printing](https://rack-maker.cbnsndwch.dev/docs/editor/exports-and-printing).

## Devices

What you rack: mini PCs, switches, routers, power. Each has a size, ports and a weight. If yours is missing, [model it](https://rack-maker.cbnsndwch.dev/catalog/model) in the [device modeler](https://rack-maker.cbnsndwch.dev/docs/modeler).

## Projects

One rack and what is in it. A project has a random 21-character id, and its link is all it takes to open and edit it, from any device, with or without an account. Share it the way you would share a password.

Signed in, you can **Claim** a project that nobody owns yet, to list it under your account, and then hand out a **Read-only link** instead. Projects you create are yours from the start. See [Sharing](https://rack-maker.cbnsndwch.dev/docs/editor/sharing).

## Revisions

Two things in Rack Maker keep revisions.

**Projects.** Every change is saved as you work. Saves from one browser within a few minutes fold into one revision. **History**, in the editor's right sidebar, lists them, and restoring one adds it as a new revision, so nothing is lost.

**Catalog entries** are numbered revisions. A published revision never changes: an edit makes a new revision. A project keeps using the revisions it was built with. When a newer one is published, the project offers the upgrade under **Updates available**, with a preview of what changes. See [Entries and revisions](https://rack-maker.cbnsndwch.dev/docs/catalog/entries-and-revisions).

## Namespaces

Catalog ids look like `alice/mini-pc-tray`. The first part is the namespace: your handle, for what you make. Only you can change what is in yours. Anyone signed in can copy an entry into their own namespace with **Fork**, and the copy records which entry it came from. See [Namespaces](https://rack-maker.cbnsndwch.dev/docs/catalog/namespaces).

## Access

| Who          | What they can do                                                                                                                                                     |
| ------------ | -------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Anyone       | Browse the catalog, open and edit a project by its link, open a read-only link, try the device modeler in their browser.                                             |
| Signed in    | Also create, copy, import and claim projects, draft parts and devices, use their drafts in their own projects, submit them for review, fork entries and report them. |
| Contributors | Also publish to the catalog, upload model files and add listings. Ask for this on the [Catalog](https://rack-maker.cbnsndwch.dev/catalog) page; an admin reviews each request.                       |

See [Accounts and sign-in](https://rack-maker.cbnsndwch.dev/docs/getting-started/accounts) and [Contributing](https://rack-maker.cbnsndwch.dev/docs/catalog/contributing).

## Licences and credits

Catalog data is shared under CC BY-SA 4.0 and credited to whoever made it. Model files keep their own licence. [Credits](https://rack-maker.cbnsndwch.dev/credits) lists them all, with the credit to copy when you share a build. See [Licences and credits](https://rack-maker.cbnsndwch.dev/docs/catalog/licences-and-credits).