The SPSite.OpenWeb method is designed to return specific SharePoint site from the collection of sites. This method implements several overload functions including: OpenWeb(), OpenWeb(GUID), OpenWeb(String), OpenWeb(String, Bool). All of these methods utilize constructor in it in order to get an instance of the site.

The SPSite’s OpenWeb method always returns a low node of the site specified as one of the parameters being passed for its constructor.

Here is an example of OpenWeb usage in the SharePoint

using System;
using Microsoft.SharePoint;
 
namespace contentTypeTest
{
    class SharePointApp
    {
        static void Main(string[] args)
        {
 
            SPSite site = SPContext.Current.Site;
            SPWeb web = site.OpenWeb();
 
        }
    }
}
Note: always Dispose() of your site and web objects unless they are called from within SharePonit context as in the above example. This is the reason you don’t see Dispose().