The process of subtitling is often mistaken as simply translating the spoken dialogue and spelling
it out for the audience to read. In reality, subtitling is much more than that...
The dialogue needs to be translated correctly as well as shortened as much as necessary and as little as possible.
The meaning needs to be carried over from one language to the other. Sentences may be phrased differently as long as the translation does not fall short of the original.
The text needs to be easy to read so that the main focus remains on the video and not on the subtitles. The maximum character count per line needs to be respected at all times.
Timecoding needs to be done correctly - all subtitles need to appear and disappear at the right moment. It's a special challenge as the length of a sentence often varies greatly in different languages.