Group

* Assigning a single selector to a declaration block can cause our code to 'bloat' beyond what is neccessarily required.
* We can streamline our code by using multiple selectors for a single declaration block, i.e. h1, h2, h3, h4, h5, h6 {declaration block;}
* NB. Make sure you don't place a comma after the last selector - if you do the CSS will not be applied.
* The grouping can contain different types of elements, classes and ids.
* The order that the grouping is presented does not matter.