# Extensions Overview

The following screenshot highlights some elements that are extensions. However, a single image cannot fully illustrate this, so we recommend exploring the options in more detail in the [Extension Types](#extension-types) article.

<figure><img src="https://2050077833-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fb0WSXUuM7Qx5BfREagAI%2Fuploads%2Fgit-blob-144ff1379a17da5ab346061163f98329d7be1967%2Fbackoffice-overview-customizations.png?alt=media" alt=""><figcaption></figcaption></figure>

In this section, you can find the common terms, concepts and guides used to extend the Umbraco backoffice.

## [Extension Registry](https://docs.umbraco.com/umbraco-cms/customizing/extending-overview/extension-registry)

How to register extensions or manipulate others.

## [Extension Types](https://docs.umbraco.com/umbraco-cms/customizing/extending-overview/extension-types)

An overview of the different ways to append functionality.

## [Extension Conditions](https://docs.umbraco.com/umbraco-cms/customizing/extending-overview/extension-conditions)

Make your extension appear only when certain conditions are met.


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