URL : default values

From    escience/nm   

used in a web browser   http://escience:80/nm

within a specified network ( ANU, anu.edu.au is the ISP)      http://escience.anu.edu.au:80/nm

Server : no suffix ? it must be a directory : http://escience.anu.edu.au:80/nm/

Server : is there a file named index.html  in that directory ? yes ? Let's return that one :

http://escience.anu.edu.au:80/nm/index.html

And an additional step, not usual

Browser : Oh ? That file asks me to load another one instead ? let's do it :

to    http://escience.anu.edu.au/lecture/comp1710/index.en.html


NB : About directory and file naming, lots of things are possible, but if you don't want to bother remembering more:

 

The general form of an URL has four parts

  1. A scheme followed by a colon.
    • Invokes a TCP/IP-based application level protocol
    • Schemes are: http, ftp, news, mailto, file, telnet.
  2. A server name.
    • A // followed by the host name or IP address of the server
    • Not needed if the server is the default
      • news server
      • mail server
  3. An optional port number. Standard or default port numbers are:
      ftp *
      telnet 23
      smtp 25
      gopher 70
      http 80
      nntp 119
      SSL 443
  4. A path.
    • Consisting of folders and/or files.
    • May include a file extension which identifies the type of document.
    • May also include a QUERY_STRING with arguments.

    * Ftp uses port 20 for data and port 21 for flow control.

Source : http://www.pierobon.org/iis/urlparts.htm