The URL for a website can tell you a lot about the purpose of a webpage.
.com = commercial site
.net =network provider
.org =organization
.edu =education - school or university
.mil = military website
.gov = government website
.com, .net, and .org sites are less regulated, meaning anyone can register for a website with that domain. .edu, .mil, and .gov sites are MORE REGULATED, and tend to be more reliable.
When searching for information on the "free web", you need to be critical. Here are a few reasons: