Important Concepts In Qt Quick - Visual Types
Most user-interfaces include some visual aspect. While multimodal interfaces are extremely interesting and can be very engaging and interactive (using, for example, haptic feedback and sounds to notify the user of changes in the state of an application), visual objects in a user-interface are able to convey a huge amount of information to the user at a glance.
See the Qt Quick QML Types page for the complete list of visual object types provided by Qt Quick.