Unobtrusive JavaScript is a general term that conveys a general set of guidelines or margins to the term REST.

REST is nothing but the Representational State Transfer.

We can explain Unobtrusive JavaScript as- it is not your particular JavaScript code that you generally use in your markup page.

Example

In spite of using event attributes like
Etc.

Unobtrusive JavaScript, attaches element directly by their ID or class, in the presence of the other attributes.

Functionality

MVC 3 uses the concept of Unobtrusive JavaScript in these two: