No, this does not involve a glass item and a plant named "OG". This is how browsers handle events, most commonly clicks, when nested in parent elements.

Here's an example:

var e1 = document.getElementById("e1"); var e2 = document.getElementById("e2");

// TRUE = TOP => DOWN (CAPTURING) // FALSE = DOWN => UP (BUBBLING) e1.addEventListener('click', doSomething1, false); e2.addEventListener('click', doSomething2, false);

function doSomething1() {       console.log(this.id); }

function doSomething2(e) {       alert(this.id);       e.stopPropagation(); }

The stopPropagation function prevents bubbling from happening up the hierarchy. Conversely, changing the event listener on e1 from "false" to "true", would trigger a top-down approach, bypassing e.stopPropagation() altogether!