After their wartime and scientific debut, early computers rapidly became essential for data handling in banks, airlines, insurance companies and other large businesses. Data was input using punched cards, and later terminals. Output was printed (rather badly by present standards) in reports, statements and even airline tickets, using high speed printers. In early computing courses you were told that computers consisted of input, processing, and output sections, and both input and output originally basically mostly meant paper.
Moving along several decades, we find personal computers recapitulating the history of mainframes. Major office applications on personal computers have traditionally been directed at turning digital information into printed documents. Given that personal computers have been stand alone and not networked from the earliest days, output in print was the obvious solution to presenting results to others. A printer made a computer substantially more use. The major components of Microsoft Office, Word, Excel, Powerpoint, and some of Access, continued to promote the idea that the end product of computing is a paper document.
Most office computer users are essentially untrained. They tend not to read the manuals (although increasingly the manuals are themselves online). Once they find a way of doing a task, they rarely change their approach, even when that method is inefficient. Many never learn to automate repeated tasks. I'm not writing that as a value judgment. This is simply what repeated usability studies have shown.
As a result, having worked out how to produce graphically enhanced pieces of paper, most users have probably not consciously realised that this is no longer what they mostly do with computers. Major users of mainframe computers realised some time ago that the information flow between computers was far more important than the form of the paper output. As a result, most mainframe computer operations involve data flows, not paper flows.
It follows that the same thing will more gradually occur in smaller and smaller businesses, and in personal computer use as well.
The major office application, word processing (which really means fancy printing) is essentially already irrelevant to most of the people who still use it. They are already communicating more often via email and by phone than by letter or report. The makers of office applications realise this, which is why they continually attempt to force email, news and web pages to appear more formatted and more like a traditional piece of published paper. It provides a justification for continuing to sell yesterday's obsolete and specialised tools.
Banking
Personal banking presents an almost complete example of the change from paper to digital information. One of the tests of whether a computing process is efficient is that it handles data entry only once. Banks originally went through a series of paper steps to handle a transaction over the counter.
A bank customer making a deposit would fill out a paper deposit form. A teller would enter the amount in the customer's passbook, or give out a receipt, calculate a new balance, and write that on the deposit slip. The teller would enter the cash on a cash slip and via carbon paper on a cash received list. In the back office, someone would add up all the cash slips, and all the cheques, and all the deposits, and make sure the cash and cheques equalled the deposits. The teller would add up the cash received list, and see that it equalled the back office figure. At the end of the day the teller would see that the cash on hand equalled the cash slips minus any cheques cashed. Meanwhile, in the back office, the deposit slips and cheques were entered in duplicate statements which could be compared with the customer's passbook, or with the customer's records when sent out periodically. Every now and then the balances of all the customer's accounts would be added up, and compared with the amounts received and cheques cashed.
There was a lot of hand work in banking, a lot of duplication, a lot of chances of human error, and a lot of paper involved. Banks moved into accounting machines, and then into computers, as soon as they could. It was a lot cheaper and more efficient than employing numerate clerks.
These days a bank customer deposit is entered direct into the computer system by the teller (assuming there is a physical deposit at all rather than a direct electronic deposit by a company). The customer no longer has a passbook, but may keep their own accounts on a personal computer or a PDA. The bank may send out a paper statement to the customer, but will increasingly encourage the customer to check their balances via an ATM, or via the internet or by phone. Personal banking applications increasingly automatically balance your own records directly against bank records, and never pass through a paper stage.
Business paperwork
Business to business transactions were traditionally started with a paper order, responded to with a shipping list, an invoice, an account statement, and so on. Larger businesses increasingly use electronic equivalents, or EDI. They are also starting to insist that any small business with whom they deal do the same.
Income taxes
Increasingly we are urged to lodge tax returns electronically.
Science Fiction Fandom
Originally in contact via the letter columns in science fiction magazines, then via letters, amateur magazines, and conventions. The telephone suplemented letters initally. The internet, but especially email, news groups and list servers, have essentially almost totally eliminated letter writing. Meanwhile, web pages are rapidly replacing fanzines, which are increasingly expensive to print and mail, especially compared to web pages.
Unix
Unix didn't really inherit the paper oriented past, as it was constructed by programmers for programmers, and emphasised tools that would work together for manipulating files. It emphasised networks early. The largest Unix manufacturer is named Sun, which is an acronym for Stanford University Network. Once files were reduced to paper, the Unix system lost its power over the data, so this inefficiency was best avoided.