What is a SharePoint Feature? What files are used to define a feature?
A SharePoint Feature is a functional component that can be activated and deactivate at various scopes throughout a SharePoint instances, such as at the farm, site collection, web level etc. Features have their own receiver architecture, which allow you to trap events such as when a feature is installing, uninstalling, activated, or deactivated. The element types that can be defined by a feature include menu commands, link commands, page templates, page instances, list definitions, list instances, event handlers, and workflows. The two files that are used to define a feature are the feature.xml and manifest file (elements.xml).