Short answers, pulled from the story.
Limited animation is an animation technique that uses reused elements to save time while maintaining detail levels. This approach began in 1918 when Winsor McCay used cels over still backgrounds for The Sinking of the Lusitania.
Hanna-Barbera Productions adopted limited animation after William Hanna and Joseph Barbera left MGM in 1957. They utilized this method because television screens were much smaller than theater screens, making character close-ups more effective for home viewers.
Japan made limited animation so popular that anime entered English as a loanword for its distinctive style. By 1980, Japanese animation matched or exceeded American industry standards through unique production pipelines prioritizing stylized content.
The Philippines became a major offshoring destination due to extensive cultural understanding and lower expenses compared to domestic production. American territory status provided animators with deep familiarity with Western storytelling traditions while low labor costs allowed international studios to produce high volumes at reduced prices.
Syncro-Vox technology involved superimposing film of voice actors' moving lips over static character frames. Xerography created heavier outlines in Disney's One Hundred and Dalmatians during the 1960s, while smear frames exaggerated motion blur to suggest speed without drawing every intermediate position.
Sony Pictures Animation released Spider-Man: Into the Spider-Verse in 2018 with deliberately choppy movement using fewer in-between frames. Subsequent films including The Mitchells vs. the Machines and KPop Demon Hunters adopted similar techniques alongside DreamWorks Animation productions like The Bad Guys and Puss in Boots: The Last Wish in 2022.