The Internet Archive is a massive database, probably the biggest one out there. It houses digitized versions of millions of books, journals, magazines, audiobooks, videos and much more.
It also takes “snapshots” of websites, providing a history of changes made at any given URL at any time in its history. This resource is called the Wayback Machine.
This is particularly valuable if you are looking for something that used to be available at a particular URL but is no longer there. Using the Wayback Machine you can find that information again and – invaluably if you are citing it as an academic reference or something like that – it will tell you when that information was available at that URL and when it ceased to be available. The Wayback Machine provides data on 330 billion websites!
What they say
“The Internet Archive, a 501(c)(3) non-profit, is building a digital library of Internet sites and other cultural artifacts in digital form. Like a paper library, we provide free access to researchers, historians, scholars, the print disabled, and the general public. Our mission is to provide Universal Access to All Knowledge.”https://archive.org/about
What I say
This is one of those resources that I just keep going back to! How many times have I searched elsewhere in vain for an out-of-print book only to find it on the Internet Archive!
There may be an issue with its funding; quite a lot of it seems to come from sources linked directly or indirectly to the American government. As the Society of American Archivists points out, archiving is never entirely neutral; there are always choices to be made. However, as far as I can make out, the Internet Archive is constantly expanding the frontiers of its activities, making as much material available as possible:
“Even the Internet Archive, a repository of online content, has positioned itself as a tool of accountability through the Wayback Machine and its recent endeavor to collect the 45th president’s online statements, interviews, and sound bites.”https://issuesandadvocacy.wordpress.com/2017/03/27/archivists-on-the-issues-the-neutrality-lie-and-archiving-in-the-now/
TLDR: Whatever the pros and cons of its archiving policy, the Internet Archive is too huge and comprehensive to ignore!