Angular 2 architecture consists of module , component , template , metadat , data binding , service , directive and dependency injection.Some of them are :

1. Module
2. Component
3. Template
4. Metadata

Module:

A module is a block of code that is used to perform a single task. We can build our application using these modules. Component class can be exported from a module. We can use the export statement to export the component class from the module.

export class TestComponent { }

The export statement tells us that this is a module and its TestComponent class is defined as public and it can be accessible by other modules of the application.

Component:

A Component is a basic building block for angularJS application.It is simply "a part of the web page" .

Template:

This tells the angular how to display the component.

<div>
 The name is : {{name}}
</div>

We put the template expression inside the interpolation braces to display it is value.

Metadata:

It is a way of processing a class.Suppose we have a component name TestComponent which will be treated as a class until we tell the Angular that it is a component. For this purpose, we can use metadata to tell the angular that TestComponent is a component. Metadata is attached to typescript using the decorator.

@Component({
   selector : 'testlist',
   template : '<h2>Name is Rahul</h2>'
   directives : [TestComponent]
})
export class TestComponent{ }