# How Continual fits together

> The model behind Continual on one page: what it keeps, who acts, what they may do, and how each change flows through it.

Continual keeps a **business world model**: one live model of your business that people and agents
work on together. This page shows its parts and follows one change through all of them. Each part
has its own page.

## The parts

| Part              | What it holds                                                          | Example                                  |
| ----------------- | ---------------------------------------------------------------------- | ---------------------------------------- |
| Records           | The things your business knows, as they are now                        | A customer, a deal, an invoice           |
| Ledgers           | How much, over time, as entries that are only ever added               | The general ledger; deals by status      |
| History           | What happened, who did it, for whom, and why                           | "Continual issued INV-US-12 for Ana"     |
| People and access | Who acts, and what each may do where                                   | Ana is an accountant in the organization |
| Approvals         | Which changes wait for a yes, and who gives it                         | Issuing an invoice waits for Ana         |
| Work              | Conversations with Continual, requests for people, and what is written | Ana's thread; a to-do to review a quote  |
| Metrics and goals | The numbers the business steers by                                     | Revenue this month; win rate             |
| Apps              | Bundles of all of the above for one area of the business               | Sales, Finance, Projects                 |

Three questions each have one home. **What is true now?** Records: open deals, overdue invoices.
**What happened, and why?** History. **How much, over time?** Ledgers, and the metrics read from
them.

## Follow one change

Ana, an accountant, writes to Continual: "Invoice Northstar for the confirmed order."

<Steps>
  <Step title="Continual works for Ana">
    Ana's message wakes Continual's agent, which works on her behalf. It can
    reach exactly what Ana can reach, and nothing more. See [people and
    access](/docs/concepts/members).
  </Step>
  <Step title="It drafts a Document">
    It drafts an invoice from the order's lines. An invoice is a **Document**: a
    record that becomes final. A draft has no number and can still change. See
    [records](/docs/concepts/records).
  </Step>
  <Step title="It asks before finalizing">
    Issuing the invoice binds the business, so by default an agent asks first.
    Ana gets an approval to decide, with the exact change Continual would make.
    See [approvals](/docs/concepts/approvals).
  </Step>
  <Step title="Ana approves, and the invoice posts">
    The **Issue invoice** Action finalizes the invoice: it gets the next number,
    `INV-US-12`, and can no longer change. In the same moment it posts to the
    general ledger: it debits what Northstar owes and credits revenue. See
    [ledgers and money](/docs/concepts/ledgers).
  </Step>
  <Step title="History and numbers follow">
    The invoice's Activity records that Continual issued it, for Ana, because of
    her request. **Revenue** on the Metrics page rises, and opens to this
    invoice. See [activity](/docs/concepts/activity) and
    [metrics](/docs/concepts/metrics).
  </Step>
</Steps>

Every change in Continual follows this path, whoever makes it: a person in the app, Continual's
agent, or an integration.

## Security in three layers

Every change passes three checks, in order:

1. **Access.** Does the actor hold a role that allows this change, where the record lives? Roles
   given on the organization or a project reach everything under it.
2. **Acting for.** An agent always acts on behalf of a person or a service account, with exactly
   that actor's access.
3. **Approvals.** Does this change need review first? Each actor's **authority** says how much it
   may do alone, agent or person alike. **Controls** are business rules for everyone, such as large
   payments needing a second look.

A change that passes all three runs. One that needs a yes waits as an approval. Nothing goes around
the checks, including Continual.

## Where you see it

| On the rail   | What you do there                                                       |
| ------------- | ----------------------------------------------------------------------- |
| **Continual** | Ask for work, answer questions, and work through your to-dos            |
| **Feed**      | **Coming:** read what changed across the business, written by Continual |
| **Metrics**   | See how the business is doing, and open any number to its records       |
| **Records**   | Browse the business world model: every record, app by app               |
| **Library**   | **Coming:** your sites and files                                        |

<Cards cols={3}>
  <Card title="Records" href="/docs/concepts/records" icon="folder">
    Objects, Documents, statuses, and references.
  </Card>
  <Card title="Ledgers and money" href="/docs/concepts/ledgers" icon="receipt">
    How every number adds up, from entries.
  </Card>
  <Card title="People and access" href="/docs/concepts/members" icon="users">
    Who acts, and what each may do.
  </Card>
</Cards>