How did foldable phones evolve ahead of Apple’s debut?

Apple is preparing to enter the foldable-phone market, hoping to make the format as mainstream as it did with touchscreens. Foldables began with Royole's FlexPai in 2018, followed by Samsung's Galaxy Fold and Google's Pixel Fold. Samsung and Chinese rivals steadily improved the technology, while tri-fold phones emerged in 2024, paving the way for Apple's debut.