Lokal vs global

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WindowsFormsApp8
{
    public partial class Form1 : Form
    {
        string navn = "Kat";
        public Form1()
        {
            InitializeComponent();
        }

        private void button2_Click(object sender, EventArgs e)
        {

        }

        private void btnKnap1_Click(object sender, EventArgs e)
        {
            string navn2 = "";

            navn = navn + "Hund";

            lblUd.Text = navn;
        }
    }
}