Northland Security Systems
Navigating and Searching the Web
Since so many people create web pages, the Web should be chaotic. However, underlying systems are in
place specifying how pages are organized on the Web and how they are delivered to your computer.
This system involves unique addresses used to access each web page, a unique address for each
computer, and browser features for locating and retrieving online content.
IPs and URLs
An Internet Protocol (IP) address is a series of numbers that uniquely identifies a location on the
Internet. An IP address consists of four groups of numbers separated by periods. For example:
225.73.110.102. A nonprofit organization called ICANN keeps track of IP numbers around the world.
Because numbers would be difficult to remember for retrieving pages, we use a text-based address
referred to as a uniform resource locator (URL) to go to a website. A URL, also called a web address, has
several parts separated by a colon (:), slashes (/), and dots (.). The first part of a URL is called a protocol
and identifies a certain way for interpreting computer information in the transmission process. Http,
which stands for hypertext transfer protocol, and ftp, for file transfer protocol, are examples of
protocols. Some sites use a secondary identifier for the type of site being contacted, such as www for
World Wide Web site, but this is often optional.
The next part of the URL is the domain name, which identifies the group of servers (the domain) to
which the site belongs and the particular company or organization name. A suffix, such as .com or .edu,
further identifies the domain. For example, the .com in the URL http://www.emcp.com is a top-level
domain (TLD). Several TLDs exists such as .com, .net, .org, .edu, and .gov. Table A provides a rundown of
TLDs being used today.
Suffix
.biz
.com
.edu
.gov
.int
.mil
.net
.org
Type of Organization
business site
company or commercial
institution
educational institution
government site
international organizations
endorsed by treaty
military site
Example
Billboard: http://www.billboard.biz
Intel: http://www.intel.com
Harvard University: http://www.harvard.edu
Internal Revenue Service: http://www.irs.gov
World Health Organization: http://www.who.int
U.S. Department of Defense:
http://www.defenselink.mil
administrative site for ISPs
Earthlink: http://www.earthlink.net
nonprofit or private organization Red Cross: http://www.redcross.org
Browsing Web Pages
You may already be quite comfortable with browsing the Internet, but you may not have pondered how
browsers move around the Web and retrieve data. Any element of a web page (text, graphic, audio, or
video) can be linked to another page using a hyperlink. A hyperlink describes a destination within a web
document and can be inserted in text or a graphical object such as a company logo. Text that is linked is
called hypertext.
A website is a series of related web pages that are linked together. You get to a website by entering the
URL, such as www.amazon.com, in your browser. Every website has a starting page, called the home
page, which is displayed when you enter the site URL. You can also enter a URL to jump to a specific
page on a site, such as the Video-On-Demand page at Amazon’s site, www.amazon.com/Video-OnDemand.
Searching for Content Online
A search engine, such as Google.com, Ask.com, and Yahoo.com, catalogs and indexes web pages for you.
A type of search engine, called a search directory, can also catalog pages into topics such as finance,
health, news, shopping, and so on. Search engines may seem to be free services, but in reality they are
typically financed by selling advertising. Some also make money by selling information about your online
activities and interests to advertisers.
The newest wave of search engines, including Microsoft Bing and Google Squared, not only search for
content but also make choices among content to deliver more targeted results. Such search engines
allow you, for example, to ask for a list of female tennis stars from 1900, on and they then assemble a
table of them for you. Table B shows some common search tools with their URLs and an indication of
whether they offer the ability to catalog pages in directories.
Search Tool
Ask
Bing
Dogpile
Google
MSN
Yahoo!
URL
www.ask.com
www.bing.com
www.dogpile.com
www.google.com
www.msn.com
www.yahoo.com
Type
engine
engine
engine
engine/directory
engine/directory
engine/directory
So how do search engines work? You can search for information by going to the search engine’s website
and typing your search text, which is comprised of one or more keywords or keyword phrases. For
example, to find information about the international space station, you could type space station in the
search engine’s search text box and press the Enter key. You can narrow your search by specifying that
you want to view links to certain types of results such as images, maps, or videos.
You can get more targeted search results by honing your searching technique. Effective searching is a
skill that you gain through practice. For example, typing space station in a search engine’s web page
could easily return more than eighty million results. If what you really need is the cost to build the
station, consider a more targeted keyword phrase like “space station cost.” Search engines provide
advanced search options, which you can use to include or exclude certain results. For example, you can
exclude pages with certain domain suffixes (such as .com and .net) to limit your search results to
educational and government sites. Table C offers some ways you can narrow your search by entering
your keywords in various ways.
Item
Quotes (“”)
Minus symbol (-)
Wildcard (*)
Or
What It Does
Instruction to use exact word or words
in the exact order given
Excludes words preceded by the minus
symbol from the search
Treat the asterisk as a placeholder for
any possible word
Allow either one word or the other
Example
“Pearl Harbor”
jaguar –car
*bird for bluebird, redbird, etc.
Economy 2014 or Economy 2015
A metasearch engine, such as dogpile.com, searches keywords across several websites at the same time.
For example, imagine you need to fly from Atlanta to Seattle. Instead of checking available flights on
three different airline websites, you can use a metasearch engine to check all of the airline sites at once.