Librarian's Tips for "Surfers"
Just reading the URL (address or location) of a site can give you lots of information about who produced the site and where it is located:

File extensions tell you what kind of source hosts the site:

.com = commercial (NOT computer)
www.amazon.com = enormous on-line bookstore
.gov = government
www.loc.gov = Library of Congress (federal agency)
.net = network (any site that's so large it has it's own server and hosts it's own website)
www.arab.net = Arab.net information agency
.mil = military
www.uscg.mil = United States Coast Guard
.org = organization usually non-profit
www.cancer.org = American Cancer Society
.edu = educational institution (college or university)
www.berkeley.edu = U. of California at Berkeley
.k12 = public or private school or school district delivering education below college level.
www.nuhsd.k12.ca.us = Nevada Joint Union High School District
Pages on the Internet are written in HTML (hypertext markup language) and use certain conventions in order for the information to be digitally available on the 'Net:
www=tells the computer to search the World Wide Web
@=used in e-mail addresses
/=used as a separator within URLs (addresses)
~=indicates a personal page hosted by a larger site
Several sites host or sell "homes" in cyberspace (give users a certain amount of digital space, like a file folder or mailbox) from which to post personally produced home pages. The information may be perfectly o.k. - just be aware it is produced by anyone who wants post it on the Web:
Geocities=www.geocities.yahoo.com
Tripod=www.tripod.lycos.com (more being created all the time!)
www.geocities,yahoo.com/~jdoe/drugs.html indicates /~ a personal page by "j doe" /stored in the Geocities site / about drugs. written in html.