The beauty dish and the octabox are two of the most fundamental lighting modifiers out there, but they have properties and ways of rendering your subjects that are appropriate for different circumstances. If you are new to lighting, this fantastic video will show you the differences between the two with a lot of example photos.
Coming to you from Kayleigh June, this helpful video will show you the difference between a beauty dish and an octabox. Both modifiers are highly popular with portrait photographers and can provide fantastic results depending on the sort of look you are going for. Generally, an octabox will give you softer light that makes for a good, general flattering look. On the other hand, a beauty dish offers a more contrasty look that tends to really sculpt the face and bring out texture and detail, which can be great if you are looking to show off your subject's facial structure or bring out the detail of something like intricate makeup work. Check out the video above for the full rundown from June.
And if you would like to continue learning about lighting for portraits, be sure to check out "Illuminating The Face: Lighting for Headshots and Portraits With Peter Hurley!"