angularjs external controller file results in error 'angular is not defined'

I have following controller defined in an external file but when I try to run my node server I get 'angular is not defined' error.

vaultcontroller.js

angular.module('demoapp.vaultcontroller', [])
.controller('vaultcontroller', function($scope, appFactory){

    console.log("INSIDE APP CONTROLLER.");

    $("#success_holder").hide();
    $("#success_create").hide();
    $("#error_holder").hide();
    $("#error_query").hide();

    $scope.get_all_currencies_from_vault = function(){
        console.log("VAULT CONTROLLER IS CALLED -1 ");
        appFactory.queryAllTuna(function(data){
            var array = [];
            for (var i = 0; i < data.length; i++){
                parseInt(data[i].Key);
                data[i].Record.Key = parseInt(data[i].Key);
                array.push(data[i].Record);
            }
            array.sort(function(a, b) {
                return parseFloat(a.Key) - parseFloat(b.Key);
            });
            $scope.all_tuna = array;
        });
    }
});

Here is the package.json

"dependencies": {
    "angular": "1.6.5",
    "angular-route": "1.6.5",
    "body-parser": "latest",
    "ejs": "latest",
    "express": "latest",
    "fabric-ca-client": "^1.0.2",
    "fabric-client": "^1.0.2",
    "grpc": "1.11.0",
    "morgan": "1.9.0"
},

This is the error trace:

angular.module('demoapp.vaultcontroller', [])
^

ReferenceError: angular is not defined
    at Object.<anonymous> (D:\Project-code\demo-POC\demopoc\client\vaultcontroller.js:2:1)
    at Module._compile (module.js:652:30)
    at Object.Module._extensions..js (module.js:663:10)
    at Module.load (module.js:565:32)
    at tryModuleLoad (module.js:505:12)
    at Function.Module._load (module.js:497:3)
    at Module.require (module.js:596:17)
    at require (internal/module.js:11:18)
    at Object.<anonymous> (D:\Project-code\demo-POC\demopoc\client\routes.js:5:23)
    at Module._compile (module.js:652:30)

Here is my index.html imports

<!-- require jquery and bootstrap scripts -->
    <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.5/angular.min.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.6.5/angular-route.min.js"></script>
    <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.0/jquery.min.js"></script>

Update-1 Loading vaultcontroller

in app.js file, I did following.

.when('/vault', {
  templateUrl: 'vault.html',
  controller: 'vaultcontroller'
})

And the code for vaultcontroller is posted above. Then I have done following in app.js

var demoapp = angular.module('application', ["ngRoute", "application.vaultcontroller"]);

And then imported the file in the index.html using script.

<!-- requiring the angular page -->
<script type="text/javascript" src="app.js"> </script>
<script type="text/javascript" src="vaultcontroller.js"> </script>

If any more code required please let me know. New to angular

Update-2 > Solution Ok, I got some help from @Aleksey Solovey and as he suggested I installed a separate server http-server for delivering my static files, earlier my node server was delivering static files as well. I removed that part from the server.js and I didn't get any of the above errors, it started working. And I have now two URLs 1. for static content > localhost:8080 2. For API server (written in node, uses server.js for startup) > localhost:8000

Thank you for helping out.