STUDY GUIDE
FOR LEARNING MODULE III
INTERNET SERVICES
Under construction!
Will be developed throughout the Summer, 2000.
INTRODUCTION
The third Learning Module is an in-depth
coverages of ten Internet services mentioned in LM
I, section2.2 We reverse the sequence of coverage from that in LM I,
and cover Information retrieval services first, followed by resource
access, and finally communications. Although this LM covers
all the Internet services (for completeness sake), it focuses on the really
relevant ones, like the Web, and surveys unimportant ones like the obsolete
Gopher and WAIS services. ...
COMMENTS:
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It is important
to distinguish between three concepts, "service", "application", and "protocol",
that are related to each other and are thus often misused causing confusion
among students. This was introduced in LM I and will be amplified
in LM IV, but it is worth reminding you here as well. The following
is based on definitions from the Computer Desktop Dictionary; you can amplify
your understanding by accessing Webopedia's information.
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Communications protocols are hardware and software standards
that govern data communications. (Use GuruNet to check out the general
meaning of protocols.) These standards are simply documents that
specify how a developer can write a...
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Applications are software that implement a particular protocol.
These applications are basically of two types:
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server applications which provide the the particular service like
accessing Web pages, transfering files (FTP), e-mail (SMTP), etc. that
are accessed by ...
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client applications (Netscape Navigator, WS_FTP, etc.) which
allow the user to access the particular service provided by the server.
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Services are abstract concepts that describe what the protocols
specify and the client/server applications implement.
Unfortunately a single word is used to refer to all three of these;
when I first began reading about telecommunications, I really was confused
(and what was really bad, I didn't know it!), particularily by carelessly
written magazine articles. For example people would incorrectly use
FTP to (1) refer to the action of uploading/downloading files (e.g. "I'll
FTP my file to your server.") or (2) refer to the application they use
(e.g. "I'll use FTP to transfer my file to your server."). These
missuses of terms for subtly different concepts can be very misleading
to novices. The proper expressions would be (1) "I'll upload my file
to your server". and (2) "I'll use WS_FTP to transfer my file to your server."
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Note that the term "service" is not unique to the Internet.
In the context of computers, a service is anything that is made available
on any client/server network.
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In Lab
2 you will be required to establish e-mail accounts at FSU and
on a commercial provider like Netscape or HotMail. You may not
like these as much as one you are already using. However, it is important
to remember that this course is about understanding
Cyberspace not just learning how to use specific tools. Becoming
familiar with more than one e-mail provider will facilitate that understanding
and open your eyes to different ways e-mail clients are implemented.
Of course, after you have finished that lab, you are free to use any e-mail
client you choose, but always check your FSU account becaue that is the
one place that I can easily contact you.