# What is Workflow?

Also called workflow definition, process definition.

A workflow is a defined sequence of steps that accomplishes a process, including the order of steps, the conditions that route between them, and the handling of failures. It can be expressed as code, as a declarative graph, or as a visual diagram. Making a process an explicit workflow gives it a stable identity that can be versioned, executed repeatedly, monitored, and audited.

A workflow definition is distinct from a workflow run. The definition is the template describing what should happen. A run, sometimes called an instance or execution, is one traversal of that template with specific inputs and its own state and history. Operational questions almost always concern runs, for example how many are in progress, how many failed, and where a specific one stopped.

Structure varies widely. Simple workflows are linear chains. More complex ones include branches on conditions, parallel fan out and fan in, loops with bounded iterations, waits for a timer or an external signal, and human approval steps. Rich structure gives expressiveness but makes reasoning about failure harder, since each additional path is a path that must be tested and observed.

Versioning is the recurring difficulty. Long running instances started under an old definition may still be in flight when a new definition is deployed. Systems handle this by pinning each run to the definition version it started with, by requiring changes to be backward compatible, or by explicitly migrating in flight runs. Ignoring the problem produces runs that fail on resume after an ordinary deploy.

In agent systems, workflows and agent autonomy sit on a spectrum rather than in opposition. A fixed workflow gives predictability and easy auditing but cannot handle situations its author did not anticipate. A model choosing its own steps adapts but is harder to verify. A common middle ground puts deterministic workflow structure around the outside and lets a model decide within individual steps.

## Key points

- A definition is the template; a run is one execution of it.
- May include branches, parallelism, timers, and approval waits.
- In flight runs must be pinned or migrated across versions.
- Explicit structure makes a process auditable and monitorable.
- Fixed workflows trade adaptability for predictability.

## In practice

A content review workflow starts when a draft is submitted. It runs an automated check, branches to a human approval step if the check flags an issue, waits up to two business days for a decision, and then either publishes the draft or returns it with comments. Each run records which branch it took and how long the approval wait lasted, so a backlog of pending approvals is visible without asking the reviewers.

## Related terms

- [Orchestration Engine](/en/glossary/orchestration-engine)
- [Durable Execution](/en/glossary/durable-execution)
- [Scheduled Job](/en/glossary/scheduled-job)
- [Queue](/en/glossary/queue)
- [Tracing](/en/glossary/tracing)

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