The Internet Archive discovers and captures web pages through many different web crawls.
At any given time several distinct crawls are running, some for months, and some every day or longer.
View the web archive through the Wayback Machine.
Web wide crawl with initial seedlist and crawler configuration from October 2010
TIMESTAMPS
The Wayback Machine - https://web.archive.org/web/20110107041708/http://www.searchengineoptimising.com/glossary/glossary-of-computer-and-internet-terms/webpage
Web pages are documents written in HTML and are either static (never change) or dynamic (are updated regularly) and are accessed through a browser. They are usally written in Perl, ASP or other scripts.