There are several properties that directly reflect their attribute (rel, id), some are direct reflections with slightly-different names (htmlFor reflects the for attribute, className reflects the class attribute), many that reflect their attribute but with restrictions/modifications (src, href, disabled, multiple), and so on. The spec covers the various kinds of reflection.
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8"> <!-- charset is a attribute -->
<meta name="viewport" content="width=device-width"> <!-- name and content are attributes -->
<title>JS Bin</title>
</head>
<body>
<div id="foo" class="bar foobar">hi</div> <!-- id and class are attributes -->
</body>
</html>