The iWork, iMovie, and Garage Band apps (office, video editing and music tools) were already provided free to all new Mac, iPhone or iPad owners, and are now available free for download to anyone with a device that runs macOS or iOS.
Since 2013, new owners of a Mac, iPhone, iPad or iPod Touch have been entitled to various Apple apps free of charge. However, they had to be paid for on the App Store and the Mac App Store by anyone who wanted to download them onto other older or second-hand devices.
iWork, iMovie and Garage Band are now free of charge for any user of an Apple device. Note, however, that iWork, iMovie et Garage Band require at least macOS 10.12 or iOS 10 to operate.
Apple is hoping to convince more students and companies to change over to its productivity suite which competes with Microsoft Office. Note that the iWork suite is also available online via iCloud, and can be used on any Apple device by connecting to iCloud with an Apple ID.