Let's start out with the words of caution that most places do not want to get around to pointing out, not wanting to ruin the user experience of enjoying all that's available on the Internet. At the instant 'you' make a connection to the Internet, your computer is a part of that very massive, worldwide network of computers linked to other computers. This is a critical bit of knowledge. What it means is that while connected to the Internet, your computer is just as much of a target for hackers and bad guys/girls as are the big Hosting sites, web pages, content servers .... again, your computer is just 'one more computer' on that network. So not only should you be aware that there is bad stuff out there available for you to find (intentionally or not) but that are bad folks out there looking to gain control of your computer/system to do their bad deeds. As the number of compromised computers seems to be on a continuous growth curve, it is obvious that this simple little fact is not advertised nearly enough by the retailers of new computers, ISPs providing the connections, and even most learning courses on "How to use your computer" .... the usual excuse boils down to not wanting to scare people away ...


A computer magically/mystically shows up at your house. It comes out of the box, gets plugged in, turned on .. then things get complicated. Some how, a decision has to be made about getting an ISP. Then the magic wand waving, prayers, sacrifices, and probably even 'more money' has to happen, possible actions like installing even more software might be involved ... but, eventually, there'll be something to click on that will then bring up some sort of web-page that announces that "you are there!!!" You type in a www.123.xyz address and away you go!


ISP selected
ISP generates 'your' account on their system
Your computer gets set-up .. manually, using the ISP's offered up floppy or CD, or a tech shows up and does all this for you
You click on something to tell the computer that you want to 'get connected'
Your computer connects (via modem, cable-modem, DSL-modem, carrier-pigeon ..???)
Your computer asks for an "IP Address Assignment via the DHCP utility
The ISP's system assigns your computer an IP address from their pool of 'assigned' IP addresses

• it is at this point that the Warning! above comes into play
• at this point, you are not 'on' the Internet, you are not 'in' the Internet .. your computer is now a 'part' of the Internet

You type into the browser address bar http://www.google.com∞
Your computer hasn't got a clue what that really means, so it starts looking for a 'definition' (see IP address)
First stop - does your computer have/use a 'Host' file ... if so, is there a listing in there that translates www.google.com to an IP address?

• If yes, then ... off to the Google computer that this address is tied to ...
• If no, then is there a 'local' DNS file/cache available?
  • If yes, then go that Google computer via that IP address
  • if no, then send a DNS query to your ISP's system for information
    • If yes, then go to that Google computer
    • If no, send that DNS query to your ISP's upstream for information
      • Repeat the above until 'someone' upstream finally answers with an IP address
      • or eventually fail and display some sort of "page not found" error screen

Finally managed to get a URL to resolve to an IP address ...???
Then (in this case) your browser sends an HTTP request for data to the computer sitting at that IP address (by default to Port: 80)....
eventually, that computer recognizes that HTTP request for data and starts sending a stream of HTML code to your computer ....
When enough data is received at your computer, the HTML code is analyzed, parsed, handled, and commands are then sent to your video card to start displaying data ... colors, text, pictures, blocks of stuff to be positioned just so, ad infinitum.

You read the text, look at the pictures, see that there's yet another link offered up to look at something else, somewhere else ... you click on that link ... and all that stuff above starts all over again ....

<Detail page for How the Internet Works - User - General>