> For the complete documentation index, see [llms.txt](https://resources.less.tech/less-tech/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://resources.less.tech/less-tech/modelling/action-guides/reshape/group-by.md).

# Group By

<figure><img src="/files/BGnaxZluGjQlVPvc2Eue" alt=""><figcaption><p>The Group By Action</p></figcaption></figure>

The Group By Actions is very used. It distributed data into certain groups (hence the name *group by*) and lets you aggregate some values within those groups. So "*group by customer type average session\_length*" could be translated to human language as "*put our data in the customer\_type groups and provide an average of the session length*". Group by's are used all the time and if you want an idea of they look in action, see the video below.

{% embed url="<https://www.loom.com/share/883465343b524aa2988623622531ad57>" %}
The Group By Action
{% endembed %}