What is RSS, and reading and writing RSS feeds

using System;
using System.Web.UI.WebControls;
using System.Data;
using System.Xml;
using System.Text;
using System.Net;
using System.IO;

public partial class RSSRead : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void btnRead_Click(object sender, EventArgs e)
    {
        //  create here table and columns that will be used 
        //  for storing items from the xml file for later binding into grid 
        DataTable dtable = new DataTable();
        dtable.Columns.Add(new DataColumn("ProductName"));
        dtable.Columns.Add(new DataColumn("UnitPrice"));


        //  fetch webrequest. Here, give the path of the location where rss feed is stored.
        WebRequest WebReq = WebRequest.Create("http://localhost:1086/RSS/AvgPriceList.xml");
        
        //  get webresponse from the webrequset 
        WebResponse webRes = WebReq.GetResponse();

        //  use stream to stremline the input from from webresponse.
        Stream rssStream = webRes.GetResponseStream();

        //  Create new xml document and load a XML Document
        //  with the strem.
        XmlDocument xmlDoc = new XmlDocument();

        //  loads the url from the stream
        xmlDoc.Load(rssStream);

        //  use XmlNodeList to get the matching xmlnodes from the xmldocument
        XmlNodeList xmlNodeList = xmlDoc.SelectNodes("rss/channel/item");

        //  create array of the object for creating the row
        object[] RowValues = { "", "" };

        //  Make a Loop through RSS Feed items
        for (int i = 0; i < xmlNodeList.Count; i++)
        {
            XmlNode xmlNode;

            xmlNode = xmlNodeList.Item(i).SelectSingleNode("ProductName");
            if (xmlNode != null)
            {
                RowValues[0] = xmlNode.InnerText;
            }
            else
            {
                RowValues[0] = "";
            }

            xmlNode = xmlNodeList.Item(i).SelectSingleNode("UnitPrice");
            if (xmlNode != null)
            {
                RowValues[1] = xmlNode.InnerText;
            }
            else
            {
                RowValues[1] = "";
            }
            //  creating datarow and add it to the datatable
            DataRow dRow;
            dRow = dtable.Rows.Add(RowValues);
            dtable.AcceptChanges();
        }
        //  finally bind the grid....
        grvRSS.DataSource = dtable;
        grvRSS.DataBind();
    }
}