Old movie screens used to be 4:3. Basically square, but sideways peripheral vision is a little wider than vertical.
When television became available to the public, the movie theaters needed something to keep attendance. And Panavision was introduced. It was wider (more panoramic) than basic square TV screens. Film shot in widescreen simply wasted the top and bottom of the film, creating the letterbox effect you see on some movies on TV. The aspect was 1.85:1
Why HDTV chose 16:9 (or essentially 1.78:1) as an aspect ratio, I don't know. But it's close enough to 1.85:1 that it doesn't really matter.
So, in ever competing fashion, movies are going to the ultra-widescreen aspect of 2.35:1.
When transferring a normal widescreen image to TV, there were a couple methods. One was to simply cut off the sides to make it match the old 4:3 ratio. Some scenes were too wide for that to work, so in conversion they used a 'Pan and Scan' method to try keeping as much action as possible in the limited width.
Those methods are still used today for the 'Full Screen' versions of movies, so you could say that the picture does get distorted in a way. It's not an exact replica of the original.