Explanation of code in c#

private List<string> GetExcelSheetName(OleDbConnection connection)
{
   List<string> listSheetNames = new List<string>();
   try
   {
      DataTable dtSheet = connection.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);

      foreach (DataRow drSheet in dtSheet.Rows)
      {
         if (drSheet["TABLE_NAME"].ToString().Contains("$"))//checks whether row contains '_xlnm#_FilterDatabase' or sheet name(i.e. sheet name always ends with $ sign)
         {
            listSheetNames.Add(drSheet["TABLE_NAME"].ToString());
         }
      }
   }
   catch (Exception ex)
   {
      throw new Exception("Could not read Excel sheet names\nDetails: " + ex.Message);
   }
   return listSheetNames;
}