While HTML gives structure, CSS (Cascading Style Sheets) is used to style and lay out the page. You can add CSS either inline, within the <style> tag in the <head>, or in an external file.
html:
<head>
<style>
body {
font-family: Arial, sans-serif;
background-color: lightblue;
}
h1 {
color: darkblue;
}
</style>
</head>