JavaScript is a object-based scripting language and it is light weighted. It is first implemented by Netscape (with help from Sun Microsystems). JavaScript was created by Brendan Eich at Netscape in 1995 for the purpose of allowing code in web-pages (performing logical operation on client side).
It is not compiled but translated. JavaScript Translator is responsible to translate the JavaScript code which is embedded in browser.
Netscape first introduced a JavaScript interpreter in Navigator 2. The interpreter was an extra software component in the browser that was capable of interpreting JavaSript source code inside an HTML document. This means that web page developer no need other software other than a text editor of develop any web page.

Why we Use JavaScript?

Using HTML we can only design a web page but you can not run any logic on web browser like addition of two numbers, check any condition, looping statements (for, while), decision making statement (if-else) at client side. All these are not possible using HTML So for perform all these task at client side you need to use JavaScript.

Where it is used?

It is used to create interactive websites. It is mainly used for:
  • Client-side validation
  • Dynamic drop-down menus
  • Displaying data and time
  • Build small but complete client side programs .
  • Displaying popup windows and dialog boxes (like alert dialog box, confirm dialog box and prompt dialog box)
  • Displaying clocks etc.