We structure webpages with the help of special words called tags. Tags are easy to recognize because of the angular brackets around them. 

Let's see what this <h1> tag does.

<html lang="en">
<head>
  <style>body { text-align: center; background-color: white; margin: 0px; } #profile_picture { height: 120px; width: 120px; border: 3px; border-style: solid; border-color: white; border-radius: 4px; box-shadow: 0px 0px 4px 1px lightGray; }</style>
</head>
<body>
  <h1>Hello, World!</h1>
</body>
</html>
]]>

Nice! We use the <h1> tag to mark things like titles on webpages because it makes the text more noticeable.