1.SharePoint 2007 Deployment: Features and Solutions (Reference)

Summary

This second post on my SharePoint Deployment Series is focused on the concepts of Feature and Solution. Check the first post SharePoint 2007 Deployment: Overview for an introduction and the series index.

What's a Feature?

A Feature is a package composed of a set of XML files that describe Windows SharePoint Services elements, which can be activated on a specific scope to help users accomplish a given task. To make it easier to understand, I usually say that you should use a Feature when you need to add one or more objects to SharePoint and want to allow users to easily enable or disable that option.
With a feature you can:

• Add a site column
• Add a site content type
• Add a list template
• Create a list instance
• Add custom actions to SharePoint's menus
• Install web parts, master pages, layout pages, images and other contents
• Register event handlers
• Associate a content type with an existing list
• Install a custom workflow
• Install a custom control
• Install a custom document converter

However, a feature cannot install itself. For that, it needs a solution.

What's a Solution?

A Solution is a deployable and reusable package that can contain a set of Features, site definitions and assemblies that you can apply to a site, and can also enable or disable individually. A Solution is materialized in a solution file, which is a file with a CAB-based format with a .wsp extension.
With a solution you can:

• Install Features
• Install assemblies in the GAC
• Install assemblies to the BIN folder of a web application
• Add assembly descriptions to the web.config safe controls section
• Set Code Access Security configurations
• Install files in the template folder of SharePoint (usually C:\Program Files\Common Files\Microsoft Shared\web server extensions\12\TEMPLATE)
• Install files in the root folder of SharePoint (usually C:\Program Files\Common Files\Microsoft Shared\web server extensions\12)
• Install a site definition

A Solution is the only way to automatically execute a deployment of functionality to a SharePoint server farm.