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Introduction
Custom components allow custom Visualforce functionality to be encapsulated as discrete modules, which provides two main benefits:
- Functional decomposition, where a lengthy page is broken down into custom components to make it easier to develop and maintain
- Code re-use, where a custom component provides common functionality that can be re-used across a number of pages
A custom component may have a controller, but unlike Visualforce pages, only custom controllers may be used. A custom component can also take attributes, which can influence the generated markup or set property values in the component's controller.
Custom components do not have any associated security settings; a user with access to a Visualforce page has access to all custom components referenced by the page.