A non-prop attribute is an attribute that is passed to a component, but does not have a corresponding prop defined.
For example, If you are using a 3rd-party custom-input component that requires a data-tooltip attribute on the input then you can add this attribute to component instance,
<custom-input data-tooltip="Enter your input" />
If you try to pass the props from parent component the child props with the same names will be overridden. But props like class and style are exception to this, these values will be merged in the child component.
<!-- Child component -->
<input type="date" class="date-control">
<!-- Parent component -->
<custom-input class="custom-class" />
