> ## Documentation Index
> Fetch the complete documentation index at: https://docs.thebay.cloud/llms.txt
> Use this file to discover all available pages before exploring further.

# Concepts

> The words this product uses, and what each one means.

Bay keeps a strict vocabulary, and this page is the product half of it. Every
word here is one a ten-year-old already knows — not as decoration, but because
these are also the words a coding agent learns the platform by, and a short,
plain, self-describing vocabulary is the interface rather than the skin.

<Info>
  The canonical source is [`CONTEXT.md`](https://github.com/thebaycloud/bay/blob/main/CONTEXT.md)
  in the repository, which also carries the internal vocabulary the code and the
  tables use. A term appearing in both means the same thing in both.
</Info>

## The app and its life

<ResponseField name="App" type="the thing you made">
  The only word for it. Not a project, a site, a service or a workload.
</ResponseField>

<ResponseField name="Ship" type="the act">
  What you do when you send your work out. `bay ship` — and `bay deploy` is the
  same command under its older name, permanently.
</ResponseField>

<ResponseField name="Build" type="one attempt at shipping">
  Has a beginning, an end and an outcome. A ship that fails still produced a
  build.
</ResponseField>

<ResponseField name="Timeline" type="every version, in order">
  Walkable. Moving along it is **rewind**; going back to a version that worked is
  **undo** — `bay rollback`.
</ResponseField>

<ResponseField name="Who did it" type="you, an agent, or the platform">
  Asked of every build. When nobody said, the answer is *someone* — never a
  guess, because a wrong name here is worse than no name.
</ResponseField>

## Watching and looking inside

<ResponseField name="Room" type="where a build is watched">
  At the app's own address, before the app has ever answered. Every movement in
  it stands for a real event; a room that animates without something having
  happened is a lie. Visible to the owner only.
</ResponseField>

<ResponseField name="Open" type="the moment the Room becomes the app">
  Not a transition between two pages — the same address, now answering for
  itself.
</ResponseField>

<ResponseField name="X-ray" type="what an owner sees inside their own app">
  What it is doing, what happened to it, and who is in it. Reached two ways:
  brought up over the live app at its own address, or opened as the app's own
  page. One thing seen from two sides. Never visible to a visitor.
</ResponseField>

<ResponseField name="Reading" type="everything the X-ray shows at one moment">
  A single thing, given identically to a person and to an agent — only the
  rendering differs. Every reading says what window it is true for.
</ResponseField>

<ResponseField name="What happened" type="everything the app did">
  In one place, for a person and for an agent to read. `bay logs`, `bay errors`.
</ResponseField>

<ResponseField name="Who's here" type="the people in an app right now">
  Not sessions, not active users. The people in it.
</ResponseField>

## Ways in, and what is not code

<ResponseField name="Door" type="a way into an app from outside">
  Not a route, an endpoint or an ingress.
</ResponseField>

<ResponseField name="Your own domain" type="a domain you own, pointed at your app">
  An additional Door, never a replacement one: the app keeps answering at
  `<name>.thebay.cloud`, which is the address every share link, log line and
  rebuild is still built from. See [Domains](/guides/domains).
</ResponseField>

<ResponseField name="Secrets" type="the only thing that cannot be written in the code">
  Not environment variables, not config, not settings. See
  [Secrets](/guides/secrets).
</ResponseField>

<ResponseField name="Shadow" type="a copy given real traffic that answers nobody">
  Exists so a change can be watched before it is real.
</ResponseField>

## Two words that mean the same thing

`bay ship` and `bay deploy` are one command. "Deploy" used to name two different
things — the act you perform, and one recorded attempt at it — so the act became
**ship** and one attempt became a **build**. `deploy` survives as an alias and
always will, because every script and agent prompt already written says it.