<human>:  What are the key differences between HTML and CSS?
<bot>: The key differences between HTML and CSS are that HTML is a markup language used for structuring content on a webpage, while CSS is a style sheet language used for formatting the content on the page. HTML provides the structure of the page, while CSS specifies the visual styling for each element in the HTML. HTML objects are generally split into two categories: block-level elements, which can contain groups of other elements, and inline elements, which can only contain text and other inline elements. CSS layouts utilize both these types of elements and let you control the display of text, color, font size, position and many other elements.