Please explain what #override, initState, super.initState means in simple terms - flutter

Question

I browsed these words on internet but I couldn't find a simple explanation.
#override
void initState() {
super.initState();
_loadCounter();
}
I was going through a example code on flutter cookbook > Persistence >Store key-value data on disk https://flutter.dev/docs/cookbook/persistence/key-value
Complete code:
import 'package:flutter/material.dart';
import 'package:shared_preferences/shared_preferences.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
// This widget is the root of the application.
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Shared preferences demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(title: 'Shared preferences demo'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key? key, required this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
#override
void initState() {
super.initState();
_loadCounter();
}
//Loading counter value on start
void _loadCounter() async {
final prefs = await SharedPreferences.getInstance();
setState(() {
_counter = (prefs.getInt('counter') ?? 0);
});
}
//Incrementing counter after click
void _incrementCounter() async {
final prefs = await SharedPreferences.getInstance();
setState(() {
_counter = (prefs.getInt('counter') ?? 0) + 1;
prefs.setInt('counter', _counter);
});
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text(
'You have pushed the button this many times:',
),
Text(
'$_counter',
style: Theme.of(context).textTheme.headline4,
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
), // This trailing comma makes auto-formatting nicer for build methods.
);
}
}

Answer 1

#override
points out that the function is also defined in an ancestor class, but is being redefined to do something else in the current class. It is optional to use but recommended as it improves readability.
super.initState()
forwards to the default implementation of the State base class of your widget. If you don't override, the default implementation will not be executed but the widget depends on that to work properly.
initState
is called when the widget is inserted in widget tree... it means whenever the widget with is called it would run initState function at first.... it would be called only once and if you reState that widget it won't be called again