Capron - "Computers"- Tools for an Information Age. 5th Edition)
as a Phenomenon
is a loosely configured, rapidly growing labyrinth of networks of computers
from around the world, from corporations, organisations and individuals.
The 'Net' was started by obscure military and university people as a
vehicle for their own purposes. They never in their wildest dreams thought
it would become the international giant it is today.
at the Department of Defence
In the Cold War of the 1950s, people worried about "the bomb," the United
States Department of Defence became concerned that a single bomb could
wipe out its computing capabilities. They decided to rely on not one
but several computers, geographically dispersed. The software that took
care of the packets was Transmission Control protocol/Internet Protocol
(TCP/IP). It's a universal standard. TCP does the packeting and reassembling
of the message. The IP part of the protocol handles the addressing,
seeing to it that packets are routed across multiple computers.
They called the
new set of connections ARPANet, an acronym that stands for Advanced
Research Projects Agency Network. The year was 1969. Before long, computers
from research universities and defence contractors joined the network.
But the network was limited to people who had some technical expertise
- a major reason why it was not yet of particular interest to the general
Tim and Marc
Tim Berners - Lee is arguably the pivotal figure in the
surging popularity of the Internet: He made it easy. In 1990, De. Berners-Lee,
a physicist at a laboratory for particle physics in Geneva, Switzerland,
perceived that his work would be easier if he and his far-flung colleagues
could easily link to one another's computers. He saw the set of links
from computer to computer to computer s a spider's web; hence the name
Web. A link on a web site is easy to see: it is either coloured text
called hypertext or an icon or image called a hyper region. A mouse
click on the link appears to transport the user to the site represented
by the link, and in common parlance one speaks of moving or transferring
to the new site; actually, data from the new site is transferred to
the user's computer.
invented the browser. The browser featured a graphical interface, so
that users could see and click on pictures as well as text. That first
browser was named Mosaic and it made web page multimedia possible. The
'Net' now offered both easy movement with Dr. Berners-Lee's links and
attractive images and graphical interface provided by the browser. Today
there are many competitive browsers, one of which is Netscape navigator,
produced by a company founded by Marc Andreessen and others.
The network became steadily more valuable as it embraced more and more
networks. Meanwhile, corporate networks, especially LANs of personal
computers, were growing apace. Companies and organisations, noting an
opportunity for greater communication and access to information, hooked
their entire networks to the burgeoning network. A new name, taken from
the name of the TCP/IP protocol, evolved: the Internet. The original
ARPANet eventually disappeared altogether.
the emergence of the Internet is due to four factors: (1) the universal
TCP/IP standard, (2) the web-like ability to link from site to site,
(3) the ease of use provided by the browser's graphical interface, and
(4) the growth of personal computers and their local area networks that
could be connected to the Internet.
Service Provider and the Browser
Needs: (1) a computer (2) with a modem and (3) its related
software, an Internet service provider, and a browser. An Internet service
provider (ISP) provides the server computer and the software to connect
to the Internet. A browser is the software on the user's computer that
allows the user to access the Internet via the service provider, using
a graphical interface. If accessing the Internet from a school, and
organisation, or a workplace, it is likely that these elements are already
in place. The only task would be to activate the browser and know how
to use it.
As mentioned earlier, a browser is software used to explore the Internet.
When they first came on the scene, browsers were a great leap forward
in Internet friendliness. In just a few years, vigorous competition
among browsers has made them ever more attractive and useful.
When you invoke
your browser software, it will dial up the Internet service provider
and, once successfully connected, display either the home page - initial
page - of the web site that created your particular browser or some
other site designated by your ISP. The browser shows three parts on
the screen: two very obvious chunks and a third that is just a line
at the bottom. The top part is the browser control panel, consisting
of lines of menus and buttons, to be described momentarily. The lower
part, by far the largest part of the screen, is the browser display
window. At the very bottom of the screen is a status line, which indicates
the progress of data being transferred as you move from site to site.
The browser control
panel stays the same as you travel through the Web; the browser display
window changes, showing, in turn, each new Internet site you visit.
When you first invoke
the browser, the web site window usually shows material according to
the browser vendor's wishes, usually useful information and possibly
advertisements for their products. Note that the site display is not
limited to the size of your screen. The page can be scrolled - moved
up and down - by using the scroll bar on the right; simply press your
mouse button over a scroll bar arrow to see the page move. As you move
the page, note that the browser control panel stays in place; it is
always available no matter what the browser display window shows.
First, note the browser's welcome banner, touting its own name, across
the top of the screen. Next , usually off to the right, is the browser
logo, N. The logo is active - shimmering, changing colours, - when it
wants to let you know that it is in the process of moving you to a next
site. It would be disconcerting to stare at a static screen and think
nothing is happening. Note also that the status line at the bottom of
the page will provide information about the progress in contacting and
receiving data from the desired site. If the transfer to the new site
takes too long, you can cancel the move by clicking the browser's Stop
A series of choices normally laid out across the top of the screen.
The menus are called pull-down menus because each choice , when clicked
with a mouse, reveals lower-level choices that pull down like a window
shade from the initial selection at the top of the screen. You can also
invoke commands using buttons for functions such as Print to print the
current page, Home to return to the browser home page, and - perhaps
the ones you will use the most - Back and Forward, to help you trace
sites you have recently traversed. If you rest the cursor over a button
for just a few seconds, a small text message will reveal its function.
Other offer directory options, most will perform searches for you.
The Location slot, sometimes called the address window, will usually
contain a Uniform Resource Locator (URL), a rather messy-looking
string of letters and symbols, which is the unique address of a web
page or file on the Internet. An URL has a particular format. A web
page URL (pronounced "earl") begins with the protocol http, which stands
for Hyper Text Transfer Protocol. This protocol is the means
of communicating by using links, the clickable text or image tat transports
a user to the desired site. Next comes the domain name, which
is the address of the Internet service provider (you must register each
domain name and pay an on-going fee). The last part of the domain name,
is called a top-level domain and represents the purpose of the
organisation or entity - in this case come for "commercial". In some
cases, the end of the domain name stands for the country of origin.
The last part of the URL, usually the most complex, contains directories
and file names to help zero in on a very specific part of a site. The
directory and file names, are case sensitive that is, you must type
uppercase or lowercase exactly as indicated.
URLs neglect to even mention the http:// if the first part of the domain
name is www. For those who use other browsers, advertisers figure that
a user who knows enough to get on the 'Net' to find the site also knows
enough to add the needed http://prefix. No one likes to type URLs. There
are several ways to avoid it. The easy way, of course, is simply to
click links to move form one site to another. Another way is to click
a pre-stored link on your browser's hot list - called Bookmarks
or Favourites or something similar - where you can store your favourite
sites and their URLs.
It is Java that permits the dancing icons, sound clips, flashing messages,
banners that scroll across the page - and much more. Java is a programming
language, developed by Sun Microsystems, that is used to write software
that can run on any machine hence its appeal to the multifaceted Internet.
If you have a particular interest in Java applets, check out Sun's web
page, which has links to test applets of various kinds.
Site to Site
Most browsers provide a list of clickable categories, such as sports,
weather, news, technology, and even comic strips. But suppose you have
something more specific in mind. If you know the URL in the location
box, then type in the new one - carefully - and press Enter on the keyboard.
You will be moved to the site just as if you had clicked a link. Sometimes
- too often - an URL does not work. That is , a message is returned
saying Unable to locate Server or, simply, Not Found. The former may
mean that you typed the URL incorrectly. The latter probably means that
the specific site you want is no longer on that ISP. People do move
around, and they do not always provide a forwarding address.
Learning from a distance is already available on the Internet in a variety
of forms. But there is also something different, something more grand:
a virtual university. This university goes beyond a course or two; it
offers a four-year degree. The school is sponsored by ten western states
(excluding California), created in response to the high costs of educating
college students on-site. Called the Western Governors University, the
school is an accredited regional university that exists solely in cyberspace.
The building shown is merely symbolic; the university has no physical
facilities at all. The key here is accredited, meaning that the degree
will be recognised by other institutions, including graduate schools,
throughout the country. Students get learning materials through electronic
databases, turn in paper by e-mail, and meet in online sessions using
video and voice links. Studies show that among adults, distance learning
is as effective as traditional classroom institution.
Although a browser, true to its name, lets a user browse most users
soon want to find something specific. A search engine is software,
usually located at its own web site, that lets a user specify search
terms; the search engine then finds sites that fit those terms. The
search engine will present the list of sites in some format, which varies
by search engine. Each search engine is associated with a constantly
updated database of sites and related keywords. A browser usually offers
links to one or more search engines, or a user can simply link to the
site of a favourite search engine. Initially, users are astonished at
the number of sites found by the search engine, often hundreds and perhaps
thousands. Narrowing the Search A simple one-word search will yield
many sites, most of which will be irrelevant to your purposes. If you
submit the word Utah as you search criterion, you will retrieve everything
from Utah Lake to the Utah Jazz Basketball team. The trick is to customise
you search criteria. In this case, adding the work vacation to the search
criteria will produce a list that begins with various hotels and parks
in Utah. You can refine and narrow your search repeatedly.
The AltaVista search
engine permits quotation marks. If you type "World Trade Centre" As
your search criterion, you will get results that focus on that institution.
If, instead, you type World, Trade, and Centre as just three words in
a row, the search engine will find every instance of each of the three
words, alone and in combination -possibly several thousand sites. Most
search engines offer operators with special functions, based on a mathematical
system called Boolean logic. The operators most commonly used are AND,
OR and NOT. The words can be further qualified with parentheses. AND
means both; OR means either or both. Used correctly, these simple words
can reduce search output to a dozen relevant sites instead of thousands
of unrelated ones. For example, suppose you want to go to school in
Illinois but want to live in a tow smaller than Chicago, and you want
to inquire about tuition. Try Illinois AND NOT Chicago AND (college
OR university AND tuition AND admission). This query is quite specific
and it will produce mostly desired sited.
Hot Search Engines
Search engines vary widely in size, content and search methodology.
Keeping this in mind, serious researchers sometimes put the same query
to each of several search engines. Ø
Your Own Home
Web pages are often written directly in a language called HyperText
Markup Language, more commonly known as HTML. The HTML code uses a set
of tags that tell your web browser how to format, load, and align text
and graphics on your page. A tag, for example, might note that a particular
line should be a title or a heading or be bulleted. Nothing stands still
for long in the computer world, so others have come along with easier
software to provide a simple user interface for writing HTML code. They
essentially just offer easier ways to specify what you want, then they
convert it to HTML for you.
Business on the
An Intranet is a private Internet- like network internal to a
certain company. Every Fortune 500 company either has an Intranet or
is planning one, Levi-Strauss, Ford, Silicon Graphics.
Taking the Intranet one step further, Intranet-to-Intranet that is hooking
up the Intranets of two companies is called an extranet.
No one envisioned today's millions of users, some surfing for hours
at a time and sending high-volume multimedia data. The Internet is a
victim of its own success, its arteries so clogged that a user often
crawls and stutters through cyberspace.
Tip: BTW, I'm
regularly post messages on newsgroups have developed their own shorthand,
which you might find puzzling at first glance. Here are some clues.
BTW stands for by the way. ROFL means rolling on the floor laughing.
Or try IMHO for in my humble opinion. FWIW for what it's worth: CUL
see you later, or (if you are up to it) TTFN ta ta for now Ø
If you have a passion for herbal remedies or for Macintosh computers
or for Chinese politics, you can find not just one person but an entire
group of people who share your interest and have something to say about.
Today there are more than 10,000 newsgroups. All of them offer conversation,
and many offer files to download. Think of a newsgroup as one large
bulleting board, marked off by category. If you happen along, you can
read other peoples postings. If you wish to respond to a message or
just contribute your own original thought, you leave a message. The
process is just about that simple.
A suggested rule
is that you observe the newsgroup for a while, an activity called lurking,
before you jump in. There are a few problems associated with newsgroups.
The one that can affect anyone is that newsgroups are a great source
for picking up e-mail addresses, which can then be used for direct advertising.
If you were selling, say a recipe for home-made acne relief, for example,
what better target for your sales pitch than the participants in the
herbal remedies newsgroup?
Not Quite Perfect
For example, users are admonished not to type in caps (IT'S LIKE SHOUTING)
The Visual Internet
Finding what you want
Although shopping on the Internet is more convenient than traipsing
around by car and foot, you are still faced with the prospect of searching
for what you want, store by Internet store. What if there was a better
way? What if you could just say what you wanted and have the computer
search through the "stores" for you? One possibility is a search engine,
described in Chapter 7, a site that allows you to type in a request
of one or more words. The search engine then returns lists of sites
matching your search words. You merely click on the name of a desired
site to be transported there. Search engines, by the way, are not just
for shopping; they can come in handy any time you need to find something
specific on the 'Net'.
Standards for secure transmission of transactions through he Internet
are still evolving. For this reason, some people prefer to do their
shopping on the 'Net' but to place the actual order by telephone or
some other secure means.
Such a bargain!
If you are a comparison shopper, you will be delighted to discover that
merchandise offered via the 'Net' is often a bargain. This is because
overhead is low when compared to physical retail stores and even when
compared to shopping by mail. No attractive displays no sales people,
no security devices clipped to merchandise, no printed catalogues, and
possibly even no advertising. And, of course, a successful business
has a potentially worldwide audience and can thus purchase in high volume
and pass the savings on to consumers.
The latest and Greatest
Computer users are sometimes so anxious to make sure that they have
the best and latest that they stand frozen in time, afraid to buy something
that might be out of date in moments. The software called Oil Change
addresses that issue by making sure your computer is running the most
current version of any software you use. Oil Change first makes a list
of all the software on your hard disk. Then it scouts out the latest
versions of the software on the Internet. The new versions of the software
arrive from the Internet via your modem and self-install. It doesn't
get any easier than that. Internet Exercises…….
the Network |
Train the Trainer | Resources/Links
on the Web