This class is a specialized collection for holding cookies. It's used by HttpWebResponse to represent a set of cookies returned by a server. By default, the IsReadOnly property is set to true . public class CookieCollection : ICollection, IEnumerable { // Public Constructors public CookieCollection ( ); // Public Instance Properties public int Count {get; } // implements ICollection public bool IsReadOnly {get; } public bool IsSynchronized {get; } // implements ICollection public object SyncRoot {get; } // implements ICollection public Cookie this [int index ]{get; } public Cookie this [string name ]{get; } // Public Instance Methods public void Add (Cookie cookie ); public void Add (CookieCollection cookies ); public void CopyTo (Array array , int index ); // implements ICollection public IEnumerator GetEnumerator ( ); // implements IEnumerable } Returned ByCookieContainer.GetCookies( ) , HttpWebResponse.Cookies Passed ToCookieContainer.Add( ) , HttpWebResponse.Cookies |