APIs and JavaScript

API = Application Programming Interface

HTML5 APIs are sets of commands for interacting with page elements.

Simple JavaScript:

<script type="text/javascript">
alert('Hello, world.');
</script>
      

API call:

<script type="text/javascript">
var c = document.getElementById('test-canvas').getContext('2d');
c.fillStyle='#f00';
c.fillRect(0,0,100,100);
</script>