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About URLs

The Uniform Resource Locator (URL) is what the WWW uses to find the location of files and documents from computers on the Internet. On your web browser screen, the URL for a document is typically displayed in the upper part of the Web browser window. The URL includes:

• an identifier for the type of Internet server;
• an Internet address; and
• a file path to the particular item of interest.

How are URLs Structured?
The structure of a URL is:

type://internet address/directory/subdirectory/.../filename
The "type" indicates the type of Internet server being accessed: http
a web server, "Http" stands for HyperText Transfer Protocol, the usual web pages.

gopher
an Internet Gopher site or menu driven directories of files and information.

ftp
an anonymous File Transfer Protocol (FTP) site, a way to transfer files.

telnet
logs you on remotely to another computer.

WAIS
Wide Area Indexed Server -- a site to search a collection of subject-oriented documents by keywords.

file
A file on your local computer system (hard drive, floppy, local file server).

The type is always followed by "://" and the Internet address of a remote computer. This has the structure of:

host.domain.domain.domain

For example:

machine.department.college.edu
pdg.lbl.gov (Part of my home page address. It is for the computer that acts as server for Particle Data Group, LBNL, and government.)
123.45.6.78
office.company.com
agency.branch.gov
machine.organization.country

edu is for educational institutions, gov for government, org for non-profit, se uk for United Kingdom, etc.

If the URL is to the main level of its host (its "home page"), then the URL is terminated with a slash "/". If you are linking to a sub-directory or a file, you must also add the exact path to that item using the slash character to indicate the entire file path.

Note: For most web servers spelling does count! So does capitalization (after the first /). File names on UNIX computers are case sensitive, meaning that a file named

SpiffyText.html is a different file than spiffytext.html.

Copy an URL:
You can go to the URL, copy the link from the top bar - or you can right-click on the link and choose "Copy link to clipboard", go to your document and paste it in.

Check yourself:

• What do the words before any slashes of a URL tell you?
  
• Where do capitals matter in an URL?

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Project Contact: Andria Erzberger
Last Update: January 29, 2003