HTML element to Select. This can be 'h1', 'p', 'body' which will select all of these elements in your HTML doc.
Within each element, a class can be assigned through the syntax 'class="x". This is accessed through dot notation in CSS. For Example '.x'
Similar to class, an ID can also be assigned however this is limited to one selector per HTML document. This is more specific than both class and selector. Accessed through # notation. For Example '#x'