Any time you have sections of your UI that update automatically, Knockout.js can help you implement it in a simpler, more maintainable fashion.
Now, with Knockout, we can say hello to more structured code based on true object orientation & declarative bindings. This means that Knockout brings the MVVM pattern comes to the web.
Knockout can be added on top of your existing web application without requiring major architectural changes. Developers familiar with Ruby on Rails, ASP.NET MVC, or other MV* technologies may see MVVM as a real-time form of MVC with declarative syntax. In another sense, you can think of KO as a general way to make UIs for editing JSON data… whatever works for you :)
The best way of explaining Knockout.js is to actually show you. In order to keep this post short & sweet and on to the point - here's a link to the interactive tutorials found on the website - knockoutjs.com
I've uploaded an simple example based on my demo on SkyDrive OneDrive
Enjoy experimenting & happy Knocking!<