# What is a workflow?

A workflow is a list of steps GoRunner does for you, in order, each time something happens.

![A form starts the workflow. Add a row runs, then Big order? sends big orders to Send an email; the others go on with nothing more.](https://docs.gorunner.io/img/build/wf-canvas-light.jpg)

```
Trigger A form is sent (Form)
01 Add a row (Google Sheets)
02 Big order? (Branch)
  Amount over 1,000
    03 Send an email (Gmail)
  Otherwise
```

The number is the step’s place in the order.

## The trigger: what starts it

Every workflow starts with one [trigger](https://docs.gorunner.io/glossary#trigger), such as:

- someone sends a form (**Form**);
- a set time comes round (**Schedule**);
- an email arrives (**Gmail**);
- another app sends data to the workflow’s address (**Webhook**);
- you start it by hand (**Manual**).

## Steps: what it does

Each [step](https://docs.gorunner.io/glossary#step) does one thing, usually in an app: add a row in Google Sheets, or send an email in Gmail. Steps run in order, from the top.

A step can use what came before it, such as the email address someone typed into the form. You write that as an [expression](https://docs.gorunner.io/glossary#expression): `{{trigger.body.email}}`.

Some steps choose the path. **Branch** takes one path or another, by a condition. **Loop** repeats steps for each item in a list.

## Draft, test and publish

What you edit is the [draft](https://docs.gorunner.io/glossary#draft). Press **Test** to run the draft once and see what each step did.

Press **Publish** to make the workflow **Live**. From then on, its trigger starts it. Later changes stay in the draft until you publish again. Each publish is saved as a version you can go back to.

So a workflow is **Draft** (never published), **Live**, or **Paused** (unpublished).

## Runs: each time it happens

Each time a workflow starts, that is a [run](https://docs.gorunner.io/glossary#run). When a step fails, the run stops there:

**Runs** lists every run with its state, such as Worked or Failed. See [Runs](https://docs.gorunner.io/build/runs#states).

## When a step fails

By default, the run stops there and is **Failed**. You can change that for each step, under **Error handling › On error**:

- **Stop the run**, the default;
- **Continue** with the next step;
- **Run error steps**: take a path of their own, for example to email you.

**Can a workflow run another workflow?**

Yes. A **Sub-flow** step runs another workflow and waits for its result. The other workflow starts with the trigger **When Called by Another Workflow**.

[Run another workflow](https://docs.gorunner.io/build/run-another-workflow)

**How many runs can happen at once?**

As many as your account allows, unless you set a **Concurrency limit** in the workflow’s **Settings**. At the limit, new runs **Wait in line**, or **Refuse** turns them away. Tests from the editor never wait.

[Limit runs at once](https://docs.gorunner.io/build/runs-at-once)

## For developers

Over the API, a workflow is a tree in JSON: the `trigger`, then each step’s `nextAction`. A step’s settings live in `config`, including `config.onError`. See [Workflow definition](https://docs.gorunner.io/api/workflow-definition).

```
Trigger A form is sent (Form)
01 Add a row (Google Sheets)
02 Big order? (Branch)
  Amount over 1,000
    03 Send an email (Gmail)
  Otherwise
```

## Related

- [Build your first workflow](https://docs.gorunner.io/build/first-workflow): A form that adds each answer to a Google Sheet · 10 min
- [Choose a trigger](https://docs.gorunner.io/build/choose-a-trigger): Which trigger fits which job · 3 min
- [Use data from earlier steps](https://docs.gorunner.io/build/use-data-from-earlier-steps): Put a form answer into an email · 5 min

Source: https://docs.gorunner.io/build/what-is-a-workflow