Configuration block – This block is executed during the provider registration and configuration phase. Only providers and constants can be injected into configuration blocks. This block is used to inject module wise configuration settings to prevent accidental instantiation of services before they have been fully configured. This block is created using config() method.
angular.module('myModule', []).config(function (injectables) {
  // provider-injector 
  // This is an example of config block. 
  // You can have as many of these as you want. 
  // You can only inject Providers (not instances) 
  // into config blocks. 
}).run(function (injectables) { 
  // instance-injector 
  // This is an example of a run block. 
  // You can have as many of these as you want.
 // You can only inject instances (not Providers)
 // into run blocks 
});
Run block – This block is executed after the configuration block. It is used to inject instances and constants. This block is created using run() method. This method is like as main method in C or C++.
The run block is a great place to put event handlers that need to be executed at the root level for the application. For example, authentication handlers.

A module might have dependencies on other modules. The dependent modules are loaded by angular before the requiring module is loaded.

In other words the configuration blocks of the dependent modules execute before the configuration blocks of the requiring module. The same is true for the run blocks. Each module can only be loaded once, even if multiple other modules require it.

Global API provides you global functions to perform common JavaScript tasks such as comparing objects, deep copying, iterating through objects, and converting JSON data etc. All global functions can be accessed by using the angular object. The list of global functions is given below:

angular.lowercase - Converts the specified string to lowercase.
angular.uppercase - Converts the specified string to uppercase.
angular.forEach - Invokes the iterator function once for each item in obj collection, which can be either an object or an array.

angular.isUndefined - Determines if a reference is undefined.
angular.isDefined - Determines if a reference is defined.
angular.isObject - Determines if a reference is an Object.

angular.isString - Determines if a reference is a String.
angular.isNumber - Determines if a reference is a Number.
angular.isDate - Determines if a value is a date.
angular.isArray - Determines if a reference is an Array.
angular.isFunction - Determines if a reference is a Function.
angular.isElement - Determines if a reference is a DOM element (or wrapped jQuery element).

angular.copy - Creates a deep copy of source, which should be an object or an array.
angular.equals - Determines if two objects or two values are equivalent. Supports value types, regular expressions, arrays and objects.

angular.bind - Returns a function which calls function fn bound to self
angular.toJson - Serializes input into a JSON-formatted string. Properties with leading $$ characters will be stripped since angular uses this notation internally.

angular.fromJson - Deserializes a JSON string.
angular.bootstrap - Use this function to manually start up angular application.
angular.reloadWithDebugInfo - Use this function to reload the current application with debug information turned on.

angular.injector - Creates an injector object that can be used for retrieving services as well as for dependency injection

angular.element - Wraps a raw DOM element or HTML string as a jQuery element.
angular.module - Used for creating, registering and retrieving Angular modules.

To prevent accidental name collisions with your code, Angular prefixes names of public objects with $ and names of private objects with $$. So, do not use the $ or $$ prefix in your code.

Filters are used to format data before displaying it to the user. They can be used in view templates, controllers, services and directives. There are some built-in filters provided by AngularJS like as Currency, Date, Number, OrderBy, Lowercase, Uppercase etc. You can also create your own filters.

Filter Syntax 
{{ expression | filter}}

Filter Example 
<script type="text/javascript"> 
{ { 14 | currency } } //returns $14.00 
</script>