3. To Recap:
• URL stands for Uniform Resource Locator.
• Every website has their own unique location
and address. The URL leads to that location.
• URL’s are just like a home address.
5. What do those mean?
• Protocol: rules determining the format and
transmission of data
• Common protocols are:
• http:// - used for the World Wide Web
• telnet:// - used to access command line interfaces
• ftp:// - used to transfer files from one host to another host
• mailto: - used to open the new message window of the
user's email client
6. What do those mean?
• Next comes the Domain/Host or an IP
address.
• This part of the URL gives the destination
point.
• Domain names are not case sensitive.
• In other words, the domain name leads you to
the specific Web server computer.
7. What do those mean?
• Domains have a suffix to inform you what type of
organization is operating the network.
• The most common suffixes are:
• .com - a commercial entity. Anyone can use these.
.org - a non-commercial entity. These can include
associations, clubs, and other organizations.
.edu - a school, college, or university. Use of these suffixes
is restricted.
.gov - government entities. Use of these suffixes is also
restricted.
.net - network operators. Use is restricted to organizations
operating Internet network services.
.mil - military sites. Nobody gets these except the military!
8. What do those mean?
• Pathway: used to find the resource requested.
• Paths are case-sensitive
• The path leads to one specific network resource
on the host.
• Resources are normally located in a host
directory or folder.
• When the location element is omitted, the URL
conventionally points to the root directory of the
host and often a home page (like 'index.htm').
9. What do those mean?
• In the pathway are directories and files.
• Directories are separated by /’s, so on
Nfl.com/videos, the Directory we are looking
in is the video directory.
• Files are the specific file in the Directory.
• An analogy might be a library. The directory is
the specific bookshelf and the file is the
specific book on that bookshelf.
10. History
• The Uniform Resource Locator was created in
1994 by Tim Berners-Lee and the URI working
group of the Internet Engineering Task Force
(IETF)
• The format combines the pre-existing system of
domain names (created in 1985) with file path
syntax, where forward slashes are used to
separate folder and file names.
• Time Berners-Lee has said that he regrets putting
in the slashes and wishes he would have stuck
with dots.
11. Absolute Vs. Relative URLs
• Full URLs featuring all three substrings are
called absolute URLs.
• In some cases such as within Web
pages, URLs can contain only the one location
element. These are called relative URLs.
• Relative URLs are used for efficiency by Web
servers and a few other programs when they
already know the correct URL protocol and
host.
12. To Remember
• Url= a uniform (same throughout the world)
way to locate a resource (file or document) on
the Internet.
• The URL specifies the address of a file and
every file on the Internet has a unique address
just like a street address.
• Web software, like browsers, use the URL to
retrieve a file from the computer on which it
resides.
