Personal computers and the internet. I remember when computer filled up entire rooms and nobody thought there would be computers in the home, much less the type you could carry around with you and phones that could acces the internet.
My first PC did not have a hard drive and had to be booted from 5.25 inch floppy disks every time I turned it on. Any work I did had to be saved to floppy disks as well My first hard drive was only tiny by coparison, only enough to hold the essential applications programs. Still saved to floppies. And there was no internet yet.
When the internet came along, there wasn't much at first, But it has made finding information and sending information so much easier, and cheaper than mailing manuscripts to publisher.