How are things archived?

We, as a modern society, are producing an enormous amount of content these days and I’m wondering what types of schemes we’ve come up with to store and archive all of this. It seems like shows like The Daily Show routinely pull up news clips from 5 or 10 years ago so there must be some system by which they can pull up this content.

I’m assuming the major networks keep a copy of their broadcasts but what about local news stations? Community public access channels? If I wanted to see the July 18th, 1994 nightly news from Muncie, Indiana, how would I go about doing that?

What about ads? Are they archived by some central authority or is it up to the owners of the ads to figure out how to store them?

Are newspapers routinely stored? I know large newspapers like the New York Times have their complete historical archive but what about regional newspapers? Is each copy stored indefinably or do they get discarded after a certain number of years?

What about books? I know the Library of Congress is vaguely involved somehow but I’m not clear on the specifics.

Also, songs, movies, radio broadcasts, etc. How are all these things archived?

The big news shows have digitized their entire archive and have hundreds of Terabytes of Video they can access at their fingertips and exponentially more stored on optical disk. (DVDs, etc)

Newspapers, even small town presses, are stored on microfiche or, in more recent years, purely digitally.

Television stations store their local programming on tapes, but not you’re standard home VHS tapes. Their’s are a little bigger. Again, for more recent years, they may be purely digital. Not every old show still exists in archive. That specific news program may be in the archive or a rat may have chewed through the only copy. But you can always mail the station and ask for a copy and for a fee (anywhere from $15 to $300 and up) they will provide you a copy. For a smaller fee, they’ll have a transcript sent (which is going to be a photocopy of something typed or printed in 1994, but in more recent years could be a purely electronic version)

The Library of Congress, in theory, has a copy of every book printed. They do not loan these out and most of them are just stored warehouse style. Again, they’ve had issues with rats and water and not everything they’ve ever recieved has survived intact. In the modern age, everything has an electronic copy and the Library of Congress is working hard to create a digital copy of everything they have. - well as hard as they can on the budget they have to work with.

Songs are kept on their masters - and can be lost. Again contemporarily they are digitized. There are hundreds of known songs that no known copies exist any longer but did at one time.

Movies, ditto, but hundreds if not thousands of early movies were lost to the ages during a fire in one of the studio’s archives.

But the digital age is not perfect. It allows for many copies in multiple locations for security. But mistakes happen. Some movies in the archive had to be spliced back together from film sent out to theatres because the masters were lost.