What does the number beside the icon represent? : <p>What does the number mean in read and why does it increment from 1 to 2? It looks similar to firebugs error count, but there are no errors here.</p>

<p><a href="https://i.stack.imgur.com/Ji3q0.png" rel="noreferrer"><img src="https://i.stack.imgur.com/Ji3q0.png" alt="enter image description here"></a></p>
