An identifier that allows multiple elements in an HTML document to be
styled in the same way

CSS , (Possibly Divs)

Explanation:

I have picked CSS, and possibly Div's as my main explanation and answer here is why.

CSS - Cascading Style Sheets, this allows you to edit multiple elements in a HTML document, such as the color or any CSS attribute.

If you would like to learn more about CSS, and the multiple options that CSS provides such as Internal Styles, External Styles, lastly In-line styles. I highly recommend the resource "W3Schools".

DIV's - Divs are basically like a container, where you can input styles into this container that can effect those elements such as if I want the background-color, of the div it would effect all the elements inside that div. However, I said this could be a possibility since it isn't CSS where it is styled however you can group these elements to one div. You can also edit the CSS of the Div to effect it.

looking away, slouching, not focusing

explanation: