Two years ago I've uploaded a video of the Lufthansas Boeing 747 "D-ABYA" to Youtube. I am currently receiving some angry comments on that video because the title reads "747-830 with new Lufthansa livery performs low pass at Hanover Airport". Many people are angry with the label "747-830", telling me that no such thing exists and that the featured airplane is a 747-8 or a 748.
Back when making the video, if I recall correctly, I looked up the type on Jetphotos. It reads "Boeing 747-830". The same is true on Flightradar24. airframes.org tells me the type is B748 and the model is 747-830. However, I could not find a reference to "747-830" on boeing.com.
What are the differences between type and model? Is a type 747-8 always a 747-830? Or are there other models with a similar name (747-8xx)? Am I correct in saying that the airplane is a 747-830?