A "little" component is the most basic component: it supports options merging.
A "model" component is a little component that additionally provides supports for any model defined in the components options.
An "evented" component is a little component that additionally instantiates event firers based on events declared in the options.
A "view" component is an evented model component that supports a view.
A "renderer" component is a vew component that bears a renderer. There are additional features provided by this component type specified on the Useful functions and events section of the Renderer Component page
A component's grade should be specified using the
gradeNames option in the components defaults block, as shown in the examples below. The
gradeNames option is a string or array of strings.