A stenographer is someone who types what people say. You have to listen carefully and type very fast to be a stenographer.
On TV shows, you may have noticed someone typing everything the judge, lawyers, and witnesses say in a courtroom. That's the stenographer. To be a stenographer, you have to type or write quickly and be skilled at shorthand. The act of taking dictation is referred to as stenography. Like a photographer captures images, a stenographer captures words.