sockets - Importance of the new line " " in Java networking

Question

Well, I need a clarify of what is the importance of the " " new line in the String variable here

import java.net.*;
import java.io.*;

public class Whois{
    public static void main(String[] args){
        try{
            Socket soc = new Socket("whois.internic.net",43);
            InputStream in = soc.getInputStream();
            OutputStream out = soc.getOutputStream();
            String url = "http://www.infiniteskills.com
";
            byte[] buffer = url.getBytes();
            out.write(buffer);
            int c;
            while((c = in.read()) != -1){
                    System.out.print((char)c);  
            }
            in.close();
            out.close();
        }catch(IOException e){
            System.out.println(e.getMessage());
        }
    }
}

Note :- without the the program doesn't work correctly and no output.

Answer 1

TCP port 43 is the WHOIS protocol explained here on Wikipedia: Whois

If you see the article is says: Send a single "command line", ending with CRLF.
That's why you need the newline in your code.