Explanation:

1. Save the File to your specified distination

    // Specify the path on the server to save the uploaded file to.
    String savePath = @"c:\root\uploads\";

    // Before attempting to perform operations/ on the file, verify that the FileUpload
    // control contains a file.
    if (FileUpload1.HasFile)
    {
      // Get the name of the file to upload.
      String fileName = FileUpload1.FileName;
     
      // Append the name of the file to upload to the path.
      savePath += fileName;

      FileUpload1.SaveAs(savePath);
     }

2. Save files to a specified directory using PhysicalApplicationPath

       // specif y the upload Directory to cater the website files overwrite like web.config.
       string saveDir = @"\Uploads\"; 

       // Get the physical file system path for the currently executing application.
      string appPath = Request.PhysicalApplicationPath;