How to Retrive All Groups in SharePoint Programmatically

Steps

• Open Visual Studio in your system
• Select Console Applciation template and give as name .
• Add a Microsoft.Cleint Assembly refrence file in right side refrence tab in visual studio.
• Replace Program.cs with the source code  

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Microsoft.SharePoint.Client;
using System.IO;
namespace CSOMCodeSamples
{
   class Program
   {
      static void Main(string[] args)
      {
         // ClientContext - Get the context for the SharePoint Site

         ClientContext clientContext = new ClientContext("http://gauti.sharepoint/sites/CSOM/");
         // Get the SharePoint web
         Web web = clientContext.Web;
         // Get all the site groups
         GroupCollection groupColl = web.SiteGroups;
         clientContext.Load(groupColl);
         // Execute the query to the server
         clientContext.ExecuteQuery();
         // Loop through all the groups
         foreach (Group group in groupColl)
         {
            // Display the group name
            Console.WriteLine(group.Title);
         }
         Console.ReadLine();
      }
   }
}

Hit F5 and check the output .