// example

<script type="text/javascript src="filename">

.document.write("Hello");

</script>

.-><script>-> Opening Tag

.->src -> it's an attributes of script tag . it define source/location of script file.

.-> filename.js -> This is our script file. where filename is file name and .js is the extension

of javascript file.

.-> type -> it's attributes of script tag which tells the browser it is a javascript. this is optional now a days.

.-> text/javascript -> its type of document.

.-> document.write("Hello");-> this is a function of display data.

.-> </script> -> closing tag