my grandma takes her ipad, and types it the URL (this take ages!)
the browser in the ipad look at the url and picks out this part:
this is the domain name. you can think of it like the name of a town, like "london" or "salzburg", "bordeaux"
my ipad asks the "dns system" to tell it what the number behind the name is. the answer is 22.214.171.124
this number is something like the post code of a town, like 33000 (forbordeaux) or 5020 (for salzburg). the code is used only for technical stuff
intresting fact: grandma's ipad also has an ip-address like this. it might be 126.96.36.199
the browser sends out one "packet" across the internet. it's a bit like a postcard, with the IP-Address as the address, and a request "please give me the webpage thimble.webmaker.org/p/fl9m as the message on the card.
picture heere: from, to, message
zoom in here for more details of transmission
add images from http://commons.wikimedia.org/w/index.php?title=Special:Search&search=copper+cable
finally the postcard reaches the right computer. (after about 100 milliseconds). on that compter there's a software called "the webserver".
it reads the request and looks in it's files and folders to find the page.
it sends a reponse with the actual page (with all the html-codes in it) back on a return postcard:
picture here of another postcard
side note: if the page is too big for one card, there might several