How does a C # write text file write a carriage return line feed?

public void Writelogfile (String input)
{
Specify the directory for the log file
String fname = "C:\\inetpub\\wwwroot\\commonfunction\\upfile" + "\\logfile.txt";
Defining a File Information object
FileInfo finfo = new FileInfo (fname);

Determine if a file exists and is greater than 2K
if (finfo. Exists && Finfo. Length > 2048)
{
Delete the file
Finfo. Delete ();
}
Create a write-only file stream
using (FileStream fs = Finfo. Openwrite ())
{
Create a write stream based on the file flow created above
StreamWriter w = new StreamWriter (FS);
Sets the starting position of the write data stream to the end of the file stream
W.basestream.seek (0, Seekorigin.end);
Write "Log Entry:"
W.write ("\nlog Entry:");
Writes the current system time and wraps the line
W.write ("{0} {1} \ r \ n", DateTime.Now.ToLongTimeString (),
DateTime.Now.ToLongDateString ());
Write the contents of the log and wrap the line
W.write (input + "\ n");
Write to------------------------------------"and wrap the line
W.write ("------------------------------------\ n");
Clears the contents of the buffer and writes the buffer contents to the underlying stream
W.flush ();
Close Write Data stream
W.close ();
}
}