---
title: "Concepts"
manual: "TYPO3 Explained"
version: "11.5"
permalink: "https://docs.typo3.org/permalink/t3coreapi:extension-concepts@11.5"
source: "ExtensionArchitecture/Concepts/Index.rst"
rendered: "2026-10-21T15:30:00+00:00"
---

> [!WARNING]
> **Attention**
>
> TYPO3 v11 has reached end-of-life as of October 31th 2024 and
> is no longer being maintained. Use the version switcher on the top
> left of this page to select documentation for a supported version of TYPO3.
>
> Need more time before upgrading?
> You can purchase Extended Long Term Support (ELTS) for TYPO3 v11 here:
> [TYPO3 ELTS](https://typo3.com/services/extended-support-elts).

# Concepts {#extension-concepts}

Learn about the concept of extensions
in TYPO3, the difference between system extension and local
extensions. Learn about Extbase as an MVC basis for extension
development.

-   [Introduction](https://docs.typo3.org/permalink/t3coreapi:introduction@11.5)
-   [System and Local Extensions](https://docs.typo3.org/permalink/t3coreapi:system-and-local-extensions@11.5)
-   [Further reading](https://docs.typo3.org/permalink/t3coreapi:further-reading@11.5)