Durandal framework basics

Question

I am going through few slides in developing a SPA using Durandal and other JavaScript library.

I have a few questions:

define('projects', [],
    function() {

        
        var Projects = function () {
            this.myDataLocal = ko.observable(); 
            this.myDataFromServices = null;
        };

        Projects.prototype.activate = function (activationData) {
            this.myDataFromServices = activationData
            this.myDataLocal(activationData());
        };
     Projects.prototype.detached = function () {
            this.myDataFromServices(this.myDataLocal());  
        };

        return Projects; 
    }
  );

a. In the above code is

var Projects = function () {
            
        };

a constructor?

b. When we are adding a function to prototype ,

Projects.prototype.activate = function (activationData) {
}

will this also be considered as a constructor and executed automatically on the function load?

c. To qualify a function for a constructor is it enough if we are defining the name of the just like this?

var ProjectsSample100 = function () {

}