Short answers, pulled from the story.
VFX stands for visual effects. It refers to the process by which imagery is created or manipulated outside of a live-action shot, typically in post-production using digital tools. It is distinct from special effects, which are achieved physically on set during filming.
Oscar Rejlander created the world's first special effects image in 1857 by combining sections of thirty-two separate negatives into a single montaged print. It predates motion pictures by nearly four decades.
The stop trick is a technique in which the camera is stopped mid-shot, the scene is altered, and filming resumes, creating the illusion of a sudden transformation. Alfred Clark used it in 1895 to simulate the beheading of Mary, Queen of Scots. Georges Méliès independently discovered it when his camera jammed on a Paris street.
Georges Méliès made more than five hundred short films between 1896 and 1913. He developed or invented multiple exposures, time-lapse photography, dissolves, and hand-painted color during that period.
A matte painting is a static painted representation of a location or environment combined with live-action footage to create a seamless background. Rotoscoping is the frame-by-frame tracing or manual matting of a live-action element so it can be placed over a different background. The rotoscope device was developed by Polish-American animator Max Fleischer.
Studios that specialize in visual effects include Digital Domain, DreamWorks, DNEG, Framestore, Weta Digital, Industrial Light and Magic, Pixomondo, Moving Picture Company, Animal Logic, Reel FX Animation, Sony Pictures Imageworks, and Jellyfish Pictures.