The state is a data structure that starts with a default value when a
Component mounts. It may be mutated across time, mostly as a result of
Props (short for properties) are a Component’s configuration. Props are how
components talk to each other. They are received from above component
and immutable as far as the Component receiving them is concerned. A
Component cannot change its props, but it is responsible for putting together
the props of its child Components. Props do not have to just be data —
callback functions may be passed in as props.