extends vs implements in typescript

1class Person {
2  name: string;
3  age: number;
4
5  walk(): void {
6    console.log('Walking (person Class)')
7  }
8
9  constructor(name: string, age: number) {
10    this.name = name;
11    this.age = age;
12  }
13}
14class child extends Person { }
15
16// Man has to implements at least all the properties
17// and methods of the Person class
18class man implements Person {
19  name: string;
20  age: number
21
22  constructor(name: string, age: number) {
23    this.name = name;
24    this.age = age;
25  }
26
27  walk(): void {
28    console.log('Walking (man class)')
29  }
30
31}
32
33(new child('Mike', 12)).walk();
34// logs: Walking(person Class)
35
36(new man('Tom', 12)).walk();
37// logs: Walking(man class)