System Tag Reference | Lightning Aura Components Developer Guide

aura:application
An app is a special top-level component whose markup is in a .app resource.

aura:dependency
The <aura:dependency> tag enables you to declare dependencies, which improves their discoverability by the framework.

aura:event
An event is represented by the aura:event tag, which has the following attributes.

aura:interface
Interfaces determine a component's shape by defining its attributes. Implement an interface to allow a component to be used in different contexts, such as on a record page or in Lightning App Builder.

aura:method
Use <aura:method> to define a method as part of a component's API. This enables you to directly call a method in a component’s client-side controller instead of firing and handling a component event. Using <aura:method> simplifies the code needed for a parent component to call a method on a child component that it contains.

aura:set
Use <aura:set> in markup to set the value of an attribute inherited from a component or event.