SizedBox is a widget used to enforce a specific size for its child or to create empty space. It's particularly useful when you need to set explicit dimensions or add space between widgets.

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('SizedBox Example'),
        ),
        body: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              Container(
                color: Colors.blue,
                height: 100,
                width: 100,
                child: Center(child: Text('Box 1')),
              ),

              SizedBox(height: 20), // Adds 20 pixels of vertical space


              Container(
                color: Colors.green,
                height: 100,
                width: 100,
                child: Center(child: Text('Box 2')),
              ),


              SizedBox(width: 20), // Adds 20 pixels of horizontal space

              Container(
                color: Colors.orange,
                height: 100,
                width: 100,
                child: Center(child: Text('Box 3')),
              ),


              SizedBox(
                width: 200,
                height: 50,
                child: ElevatedButton(
                  onPressed: () {},
                  child: Text('Button'),
                ),
              ),


              
            ],
          ),
        ),
      ),
    );
  }
}