If you've bought an iOS or Mac device in the past few years, Apple's suite of creativity and productivity apps was effectively free for you. Sure, you had to pay for that expensive tablet or laptop, but the apps themselves were included in the purchase, even if you didn't download them until later. Starting today, however, Apple is simplifying things and making Keynote, Numbers, Pages, iMovie and GarageBand all free in the App Store for anyone in their ecosystem.
As MacRumors notes, the change in pricing is meant to make it easier for businesses and educational institutions to get the iWork suite through Apple's Volume Purchase Program. That said, this is still a great opportunity for anyone still running older hardware to give Apple's in-house apps a try. You'll certainly never find a better price on GarageBand.
iWork apps require macOS Sierra to run, but GarageBand is available for machines running Yosemite or later and iMovie will run as long as you're up to El Capitan or higher. On mobile devices, iWork requires at least iOS 10.0, while iMovie and GarageBand require at least iOS 9.3 and iOS 10.2 respectively.