As others have said, marketing term. FYI: no matter what you try to do, you'll also find it is not "magical." You'll find no fluid to pour or even move in "Liquid Retina" and "all day battery life" will or will not work depending on how you define a day. "More powerful than fastest Wintels" will only actually play out if it is measured however it was measured by Apple Marketing to be able to spin such stuff and probably not break truth in advertising laws (even some of the biggest fans on YouTube channels are struggling to replicate whatever was used to drive the charts shown at the launch).
Marketing uses key words like may, up to, could, potential, etc to spin incredible claims but the (let the) buyer (beware) has the responsibility to recognize potential spin from reality. "All screen design" comes down to how one defines screen. They might also claim "all screen phone."
Similarly, "unlimited" usually has many limits, "infinite" is usually finite, wireless speed potentials commonly slung are nearly impossible to replicate in reality, 5GE is not 5G, "your milage may vary", "service may be throttled", "<medicine> may not work", "past performance is not indicative of future performance," etc.
But let's leave the best poke to the master... George Carlin...
In only 10 minutes, he shreds the entire spin:reality landscape. Did anyone do truth humor better?