How Angular Js Works? Can I Do Angular Js Without Server Side Language ? How Can I Do Server Side Using Angular Js?

Angular JS has been designed to be used as front-end tools for the platforms such as MVC, NodeJS. What does front-end means you can do client-side operations such data input, validation, manipulations which is the feature called 2-way binding.
You can use Angular JS in MVC framework, with Web API or WCF services for the server side processing. Web API/web service with database at the back-end you can write the operations such as Insert, update, delete etc. and from angular js you can write the services/controllers to call the api/web services to get the data and to send the data. You can use simple html or HTML 5 in the view will be fine.
The security issue when you use web api/web services is done through token based authentication (OAuth) where the database actions are performed based on security token. As a result angular js is secure in that sense.

If you like to use Node JS with nosql database such as mongodb you have the option for that. MongoDB can be used language like c#.

Hope this will help you.