---
title: Span
order: 10
description: "OpenTelemetry's name for one unit of work under a trace: a target execution, whose sub-operations are child spans. An output reference points at a span's captured output."
tags: [glossary, execution-and-caching]
---

# Span

OpenTelemetry's name for one unit of work under a trace: a target execution,
whose sub-operations are child spans. An output reference points at a span's
captured output.

## Example

An output reference names one span's captured output.

```sh
magus query output out1a2b3c
```

## Used in

<!-- BEGIN GLOSSARY USAGE (generated by glossary-usage-generate from the knowledge graph; edit the generator, not this list) -->

In the code (`magus refs <name>` lists every site):

- `changeset.Span` (Go)
- `edit.span` (Go)
- `tty.Span` (Go)
- `playground.Span` (Go)
- `impact.Span` (Go)

<!-- END GLOSSARY USAGE -->

## See also

- [Telemetry](../concepts/telemetry.md)
- [Trace](trace.md)
- [Output reference](output-reference.md)