Lion offers a set of components out of the box, which are included within the lion distribution.
However, lion exposes an API to ease the creation of custom components.
The advantage of ussing lion ootb components is the fact that those components are maintained within the lion framework source code, guarantying the compatibility when upgrading to an upper version
Lion components out of the box:
The actionbox, a component able to render the result of executing a controller action
The area, a component designed to group components within an area
The checkbox, a component to check or uncheck an option
The combobox, a component to select an item within a list