In AngularJS, a provider is a special type of object that is used to define a service. Providers can be used to configure the behavior of a service before it is instantiated.

There are four types of providers in AngularJS:

1. Constant: A constant provider is used to define a value that can be injected into any other part of the application.
2. Value: A value provider is used to define a value that can be injected into any other part of the application. The difference between a constant and a value provider is that a constant can never be modified, while a value can be modified.
3. Factory: A factory provider is used to define a service by specifying a function that returns an object.
4. Service: A service provider is used to define a service by specifying a constructor function. When the service is instantiated, AngularJS will use the new operator to create a new instance of the service.

Configuration is another aspect of AngularJS that is closely related to providers. Configuration is a way to set up the behavior of an application before it is started. AngularJS provides the $routeProvider service to configure the routing behavior of an application.

Here’s an example of how to use a factory provider to define a service:

angular.module('myApp')
  .factory('userService', function() {
    var users = [];

    function addUser(user) {
      users.push(user);
    }

    function getUsers() {
      return users;
    }

    return {
      addUser: addUser,
      getUsers: getUsers
    };
  });

In this example, we define a factory provider called ‘userService’ that returns an object with two methods: ‘addUser’ and ‘getUsers’. The ‘addUser’ method adds a user to an internal array, while the ‘getUsers’ method returns the array of users.

We can then inject the ‘userService’ into any other part of the application like this:

angular.module('myApp')
  .controller('UserController', function(userService) {
    this.users = userService.getUsers();

    this.addUser = function(user) {
      userService.addUser(user);
    };
  });

In this example, we define a controller called ‘UserController’ that injects the ‘userService’ and uses it to add and get users.

Here’s an example of how to use the $routeProvider service to configure routing behavior:

angular.module('myApp')
  .config(function($routeProvider) {
    $routeProvider
      .when('/', {
        templateUrl: 'home.html',
        controller: 'HomeController'
      })
      .when('/about', {
        templateUrl: 'about.html',
        controller: 'AboutController'
      })
      .otherwise({
        redirectTo: '/'
      });
  });

In this example, we define a configuration block that injects the $routeProvider service and uses it to define two routes: ‘/’ and ‘/about’. The routes are defined using the ‘when’ method, which takes a route path and an object that specifies a template URL and a controller. The ‘otherwise’ method is used to specify a default route to use when none of the defined routes match.

Overall, providers and configuration are important concepts in AngularJS that allow you to define and configure services and application behavior in a modular and flexible way.