Create Client Context CSOM (.Net Managed Code)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Microsoft.SharePoint.Client;
using Microsoft.SharePoint.Client.Publishing;
using System.Security;
using System.Web;
using System.Net;


namespace GetContextExample
{
    class Program
    {

        //sharepoint online user id
        private const string spoUserName = "[email protected]";

        //network user id requires System.Net namespace
               //private const string netUserName = "abc\\xyz";

        private const string password = "password";
        private const string siteURL = "your site url";

        static void Main(string[] args)
        {
            //authenticating user
            ClientContext context = Auth();
            if (context != null)
            {
                // place your code here, which uses context

            }
        }

        public static ClientContext Auth()
        {
            ClientContext context = new ClientContext(siteURL);
            Web web = context.Web;
            SecureString pwd = new SecureString();
            foreach (char c in password.ToCharArray()) pwd.AppendChar(c);

            // for network credentials
                       //context.AuthenticationMode = ClientAuthenticationMode.Default;
                       //context.Credentials = new NetworkCredential(netUserName, pwd);

            context.Credentials = new SharePointOnlineCredentials(spoUserName, pwd);
            try
            {
                context.Load(web);
                context.ExecuteQuery();
                Console.WriteLine("Authentication Succesful for " + web.Title + " site");
                return context;
            }
            catch (Exception e)
            {
                Console.WriteLine("Authentication failed.");
                return null;
            }
        }

    }
}