HTML without CSS is like the bare concrete skeleton of a building. We use CSS to style, position and layout the page.
There are 3 main ways to incorporate CSS in our page
The browser calculates which selector will take precedence and be applied on the elements using specificity. usually it's quite intuitive.
EMMET makes it easier to create HTML tags using CSS selector syntax. take a few minutes to familiarize yourself, you won't look back :)