var result = arr1.Except(arr2);

using System;
using System. Collections;
using System.Collections.Generic;
using System. Linq;
using System. Text;
using System.Threading.Tasks;
namespace ConsoleApp1
{
    class Programme2
    {
        static void Main(string[] args)
        {
//create an array 'a' and 'b' type of string having the values
            string[] a = { "Rohini", "Suresh", "Sateesh", "Praveen" };
            string[] b = { "Madhav", "Sushmitha", "Sateesh", "Praveen" };
//Except method is used to return the value which does not exist in the second list 
            var result = a.Except(b);
            foreach (var item in result)
            {
                Console.WriteLine(item);
            }
                Console.ReadLine();
        }
    }
}