Two of the most common scopes used for features are ‘Site’ and ‘Web’. When using the ‘Web’ scope, the feature can be used anywhere in the Web application. If, instead you are using the ‘Site’ scope, the feature is only available in the particular Site Collection in which it’s installed.

When activating these features, there are also 2 different places you will find them listed (once installed), in order to activate them. Both of these are available to you as a developer via ‘Site Actions/SiteSettings’.

If you used the ‘Site’ scope, you would look in the ‘Site Collection Administration’ section, and click on ‘Site collection features’. However, if you used the ‘Web’ scope, you would look in the ‘Site Actions’ section and click on ‘Manage site features’ .