---
title: "Introduction into using site packages"
manual: "TYPO3 Explained"
version: "main"
permalink: "https://docs.typo3.org/permalink/t3coreapi:site-package-introduction@main"
source: "ExtensionArchitecture/SitePackage/Introduction.rst"
modified: "2026-09-14T11:10:56+00:00"
---

# Introduction into using site packages

## Site package benefits

Developing a website can be approached in different ways. A typical
website consists of HTML documents containing text and references to
image files, video files, styles, etc. Because it is an enterprise content
management system, TYPO3 has a clean separation between design, content and
functionality and allows developers/integrators to easily add simple or
sophisticated functionality.

### Encapsulation

Using extensions is a powerful way to get the most out of TYPO3. Extensions
can be installed, uninstalled and replaced. They can extend the core TYPO3
system with new functions and features. An extension typically
consists of PHP files, and can also contain design templates (HTML,
CSS, JavaScript files, etc.) and global configuration settings. The visual
appearance of a website does not necessarily require any PHP code. However, the
site package extension described in this tutorial contains exactly two PHP files
(plus a handful of HTML/CSS and configuration files) and is an *extension* to
TYPO3. You can simply copy the PHP code in this tutorial if you do not
have any programming knowledge.

### Version control

The advantage of a site package extension is that all files relevant to the website
are stored in one place and can easily be tracked in a version control system
such as Git. The site package approach is not the only way of creating TYPO3
websites but it is convenient and professional and not overly-complicated.

### Dependency management

TYPO3 extensions can have specific dependencies set to other extensions and TYPO3
versions. This is called "Dependency Management" and makes deployment easy
and fail-safe. Most TYPO3 sites are dependent on extensions such as
"News" and "Powermail". A site package extension which contains
global configuration settings for these extensions will define the dependencies
for you. When the site package extension is installed in an
empty TYPO3 instance, the dependent extensions are automatically downloaded from
the [TYPO3 Extension Repository](https://extensions.typo3.org) and installed.

### Clean separation from the userspace

In a TYPO3 installation that doesn't use extensions, template files are often
stored in the `fileadmin/` directory. Files in
this directory are indexed by TYPO3's [File Abstraction Layer (FAL)](https://docs.typo3.org/permalink/t3coreapi:fal@main) resulting in
possibly irrelevant records in the database. To avoid this the `fileadmin/`
area should be seen as a "userspace" which is only available for editors to
use. Even if access permissions restrict editors from accessing or manipulating
files in `fileadmin/`, site configuration components should
still not be stored in the userspace.

### Security

Files in `fileadmin/` are meant to be publicly accessible by
convention. To avoid disclosing sensitive system information (see the
[TYPO3 Security Guide](https://docs.typo3.org/permalink/t3coreapi:security@main) for further details),
configuration files should not be stored in `fileadmin/`.

### Deployment

TYPO3 follows the *convention over configuration*
paradigm. If files and directories in the site package
extension use the naming convention, they are loaded automatically as
soon as the extension is installed/activated. This means the
extension can easily be deployed with Composer.
Deployment can be automated by system administrators.

### Distributable

By virtue of the motto "TYPO3 inspires people to share!", the site package
extension can be shared with the community via the official [TYPO3
Extension Repository](https://extensions.typo3.org) and/or in a publicly
accessible version control system such as [GitHub](https://github.com).

Last, but not least, configuration settings in the site package can
be overwritten using TypoScript setup and constants.