> For the complete documentation index, see [llms.txt](https://docs.umbraco.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.umbraco.com/umbraco-cms/13.latest/extending/section-trees.md).

# Sections & Trees

The Umbraco backoffice consists of sections (sometimes referred to as applications) which contain Trees.

Each section is identified by its name in the top navigation ribbon of the Umbraco Backoffice.

For example, when you load the backoffice, you'll see that the 'Content' section contains one tree: the content tree. Meanwhile, the 'Settings' section contains a number of trees such as Stylesheets, Document Types, Media Types, etc...

You can create your own sections and trees to extend Umbraco.

## [Sections](/umbraco-cms/13.latest/extending/section-trees/sections.md)

Describes Umbraco Sections, configuration and APIs.

## [Trees](/umbraco-cms/13.latest/extending/section-trees/trees.md)

Describes Umbraco Trees, configuration, APIs and events.

## [Searchable Trees (ISearchableTree)](/umbraco-cms/13.latest/extending/section-trees/searchable-trees.md)

Explains how to customise the backoffice search of a Section Tree.


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