Angular Tutorial for Beginners: Learn Angular from Scratch (Part-2) смотреть онлайн

What is Angular?
Now, when we talk about Angular, we talk about Angular 2 or Angular 5. Angular is a complete rewrite of the AngularJS framework. Angular as a different approach from its predecessor.
Angular allows us to build applications across all platforms. It is an open-source platform that uses TypeScript. In a few words, TypeScript is a strict syntactical superset of JavaScript, and adds optional static typing to the language.

Architecture overview
Angular is written in TypeScript and it implements core and optional functionality as a set of TypeScript libraries that we can import.
An Angular application has, for building blocks, a thing called NgModules. An Angular app is defined by a set of NgModules. An app always has at least a Root Module that enables bootstrapping. An NgModule is made of Components. Every app has at least a Root Component.
Components, and things like Services, are just classes. They are, however, marked with decorators that tells Angular how to use them.
Angular provides a Router Service that helps us to define navigation paths among the different Views.

Modules
Angular apps are modular and this modularity system is called NgModules.
An NgModule defines a set of Components. An NgModule associate related code to form functional units. Every Angular app has a Root Module, conventionally named AppModule, which provides the bootstrap mechanism that launches the application.
Even if they are different and unrelated, NgModules, like JavaScript modules, can import functionality from other NgModules, and allow their own functionality to be exported and used by other NgModules. What we call Angular Libraries are NgModules.
We declare an NgModule by decorating our class with the “@NgModule” decorator. This decorator is a metadata object whose properties describe the module. The most important properties, which are arrays, are the following:
declarations — Components, Directives, and Pipes that belong to the NgModule
exports — the subset of declarations that should be visible and usable in the Components of other NgModules
imports — other modules whose exported classes are needed by Components declared in the NgModule
providers — list of the needed Services that, because they are listed here, become are available app-wide
bootstrap — the main application View, called the Root Component, which hosts all other app views. (only the Root Module should set this bootstrap property)


To understand about Routing in angular
https://www.youtube.com/watch?v=LerzBJ5-rCE

To understand about most common mistake in angular
https://www.youtube.com/watch?v=hAskdS9C5iE

To understand about Input and Output decorators in angular
https://www.youtube.com/watch?v=e5UdTRikaMc

To understand about Custom Directive in angular
https://www.youtube.com/channel/UCzlX2P4Y1t4clXGl7jNvTwA