Here we are going to see how the data will be communicated from parent component to child component using @Input() method.
@input() can be used in two ways.
·        Two way binding with @Input()
·        One way binding using ngOnChange() event and @input()
Here we gonna look at one way binding with ngModelChange with @Input().
Technical implementation:
            Here we have two component AppComponent (parent component) ChildComponent ( child component).
App component contains Textbox, When user enters any of the data, it will be passed to Child component and display as a span there.

import { Component } from '@angular/core';

  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']

export class AppComponent {
 public inputValue : string;
  onChange(UpdatedValue : string) :void
    this.inputValue = UpdatedValue;


import { Component, OnInit, Input } from '@angular/core';

  selector: 'child-component',
  templateUrl: './child-component.component.html',
  styleUrls: ['./child-component.component.css']
export class ChildComponentComponent {
  @Input() message:string;
  constructor() { }


Add FormsModule in the app.module.ts

That's It !!