This refers to a specific distribution of the Android operating system that has been modified to run on computers with x86-based processors, rather than the ARM architecture typically found in mobile devices. The “8.1” indicates that it is based on Android version 8.1 (Oreo), and “r1” likely denotes the first revision or release of this particular x86 adaptation. An example would be using this on a legacy desktop PC to repurpose it as a light-use workstation or media center.
The significance of such distributions lies in their ability to extend the lifespan of older hardware and offer a familiar mobile-like operating system experience on traditional PCs. Benefits include access to a vast library of Android applications, potential improvements in performance compared to older desktop operating systems on the same hardware, and a generally lightweight footprint. Historically, these projects have provided an avenue for developers and enthusiasts to experiment with Android on non-standard hardware.