==$0

Chrome maintains a stack, $

• where $0 is the selected element,
• where $1 is the last selected element,
• $2 would be the one that is selected before $1, and so on.

== $0 chrome

• Accessing DOM elements from console: $0

• Accessing their properties from console: $0.parentElement

• Updating their properties from console: $1.classList.add(...)

• Updating CSS elements from console: $0.styles.backgroundColor="aqua"

• Triggering CSS events from console: $0.click()

• And doing a lot more complex stuffs, like: $0.appendChild(document.createElement("div"))

So clicking on an HTML element and getting a reference variable ( $0) in the console