Components - the reusable objects

Components in Angular 2 are building blocks that address and provide solutions for different concerns in a web app. If we can solve one problem in one component, it means we can use that same component later in other parts of the current project or other projects. They are usually used to handle a part of a view (an HTML template). So if we create a component for a progress bar, we can use it later anywhere in the project where we need it. We can use components in other projects as well. For example, a component for a navigation bar that is created in one project, can be imported and be used in other projects in the future.

Components are basically nothing more than a class, with a bunch of methods, properties, and other usual codes. Inside the seed project that we set up in the previous chapter, open the src/app/about/about.ts file, and observe the code:

// src/app/about/about.ts 
import {Component} from '@angular/core'; 
@Component({ 
  selector: 'about...