All good. Gertrude is fairly amiable to such activity. She was preoccupied all of last evening understanding three letters.
www. Then she realised she must first understand the word
Internet. The mass of cables that holds together people around the world with information at each end of the wires. The universe's electronic
alter ego. Alter
e-go, to be more catchy.
In the real world, people talk to one another over phone, by letters or in person. The internet is a lot like that. Each method of reaching out is roughly the equivalent of a network, Gertrude reasoned. So there is etiquette, rules and even tools involved in each of these networks. All of these networks, the cables, the satellites, the attached devices and the rules, make up the internet. Not surprisingly, the networks, the cables, the satellites, the attached devices and the rules - all have names.
Gertrude has heard people say web to mean the all of the internet. She would like to tell them that the (world wide) web is the name given to only one of its networks. The internals of the
web, where people visit ebay or facebook, are different to the internals of the
POP network where electronic letters are exchanged. Networks may cross each other's paths. Like when Gertrude uses the
web to go to gmail and then
it uses
POP to send the emails to someone else. The web might still be the most frequently used network in the internet.
Within a network, each of its component has a name. The massive computers whirring away in the corners of cyberspace supplying the pages or masses of data are called
servers. In increasing order of cleverness, the names of devices that direct the data to their homes are
hubs,
switches and
routers. Cables made of copper wire, aluminium wires or even glass fibre carry the data. They are named
twister pair,
coaxial and
optical fibre in that order. There are probably names for data-carrying invisible satellites in ether whose names Gertrude isn't sure of. She knows
bluetooth can carry data wirelessly over a short distance.
Data now arrives at the
client computer that asked for the data. The computers who want to send or receive data from others of their species must have a special bone in their bodies called a
network card. These network cards have a unique serial number called a
MAC Address tattooed in them. Gertrude is fairly sure that the
IEEE and the makers of the network cards who are responsible for this are not likely to run out of large numbers any time soon.
A lot of the data on the world wide web is indexed and labelled and categorised so it can be easily be shown to people looking for them.
Spider is the name given to little programs suitable for crawling all over the web and trawling for information sitting on servers. So people take trouble to make their data extra-clear to the spiders. The spiders come back with data about the information to another program called the
search engine which classifies and organises this data about the data. To go completely the other way round, it is also possible to hide some pages from search engines. There is a
chowkidar-like program named
firewall to scrutinise the data between networks to see if it can pass through or not.
So people only need to remember the address of the
search engine. The address is called a
URL. Not even the most technical of her colleagues think of it as a universal resource locator. Humbug! Its a rather ambitious name.
The URL is typed into a
browser. A
browser understands the meaning of URLs depending on where you type it in. The URL has a lot of dots separated by words. A URL takes you where you want to go. Gertrude smiles at the verbs - for the internet - which have a lot to do with reaching out - navigate, surf, browse and address.
An address proves that a computer exists in the network. This address is a number called an
IP address. IP addresses are three dots surrounded by numbers. This is quite different to a
MAC address which is physically inscribed inside the heart of a computer. The IP address is a concept. Fickle. Not as committed as a post code. Someone responsible invents this address.
Clients have IP addresses. Servers have IP addresses. The responsible person is a
domain name registrar whose sole profession is devoted to naming or numbering. This person or organisation would need to be authorised by
ICANN, a superior group of people who assign names and numbers.
Clients may have a different IP address each time they connect to a network. It would be rather inconvenient if servers did. So servers get given a fixed IP address. Trouble is, there may be many servers who provide data on the same thing say, google. What we know as
google might actually be a colony of computers with different IP addresses cloaked under a more endearing name.
To prove this, on her little old PC, Gertrude does Start > Run > CMD and then types: ping www.google.com. And she sees an IP address. Then she does the same thing a bit later. Sure enough, a different IP address appears.
So www.google.com is a
domain name. The dot com is rather like a surname you cannot get rid of! The ICANN people have a
list of close to 300 surnames for domain names which include country codes dot co dot uk and the old fashioned dot com, dot org and the like. It is exploiting Libya's and USA's country code that unorthodox names like bit.ly, and del.icio.us have flourished.
The surname is a top level domain name. Stuff to the left of it is called a second level domain name. Stuff to the left of that is the third level domain. This can go on for a hundred and twenty seven levels. A most remarkable prime number to be chosen. 127 is
20 + 21 + 22 + 23 + 24 + 25 + 26
A top level domain name usually won't usually be a physical computer on the network. It is only the second level onwards that there are actually computers available for entertainment. At this level and beyond, they are called
hostnames.
Gertrude was just talking to Charlie yesterday who visited a place in Angelesey in North Wales to spend time in a caravan. The place is
llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogochuchaf. Now thankfully, the ICANN people allow domain names at each level to be up to 63 letters. She wonders if 63 is 1 bit short of 8 bytes (8 times 8 bits is 64 bits is 8 bytes). with the one 1 bit reserved for something secretive. Or just plain superstition. However, in all, a domain name can be
253 letters long. Presumably, this includes the many dots and the surnames.
Within a domain, there are heaps of structured and categorised pages waiting to be opened and read. Each of these pages has an address too called a URL - carefully named and decorated so that search engines spiders can find them easily. Some pages have ghastly names. Gertrude does not want to name and shame anyone right now. So no examples. But some of them have beautifully crafted ones. Like in the online version of the
guardian.
Gertrude has a carefully nurtured grouse against things like tinyurl.com and twitter, which force people to cram and zip these ornamental URLs into encrypted unsightliness causing people to get afraid of them and
ban shrunken URLs and for other people to invent things like untiny.com to unshrink the URLs.
When you type the URL in the browser and hit enter, it is called a
request to the
server, as opposed to an order or an instruction to it. So if Gertrude only types in facebook.com, the browser automatically sticks the
http://www. This is because stuff that is accessed through a browser usually is on the world wide web. Naturally it follows the rules of the web. The www - dub dub dub - stands for the web. The
http stands for the rules of the web. Hypertext Transfer Protocol. Wait a second. Shouldn't it be
hmtp://www - as in Hypermedia Transfer Protocol?
Not new year resolutions. Just plain old screen resolutions.
