Тег сценария в файл JS
<script type="text/javascript" src="path-to-javascript-file.js"></script>
Aggressive Antelope
<script type="text/javascript" src="path-to-javascript-file.js"></script><script type="text/javascript" src="path/filename.js"></script><!DOCTYPE html>
<html lang="de">
<head>
<meta charset="utf-8">
<script src="something.js"></script>
</head>
<body>
</body>
</html>