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

# Instrumentation

AppSignal provides many ways to provide more insights into your application — by adding more instrumentation or tagging the data that appears in the UI at AppSignal.com. All of the information that we collect from your application forms part of a broader **trace**, a visual representation of the flow of data through your application.

**Traces** are made of one or many spans. A Trace can be thought of as a *directed acyclic graph (DAG)* of spans:

<img src="https://mintcdn.com/appsignal-715f5a51/nF8c1Rwq1cS7b5hg/assets/images/abstract-trace.png?fit=max&auto=format&n=nF8c1Rwq1cS7b5hg&q=85&s=8e955df41909f6fadf6d607478d6badb" alt="Trace diagram" width="1826" height="650" data-path="assets/images/abstract-trace.png" />

* [The Tracer object](/nodejs/3.x/instrumentation/instrumentation#the-tracer-object)
* [Creating and using a span](/nodejs/3.x/instrumentation/instrumentation#creating-an-active-span)
* [Exception handling](/nodejs/3.x/instrumentation/exception-handling)

## Contact us

Don't hesitate to [contact us](mailto:support@appsignal.com) if you run into
any issues while implementing tracing. We're here to help.