If you are confused by the massive range of flash heads produced by Chinese manufacturer Godox, you're in luck. Professional photographer Robert Hall has produced a very useful video that aims to explain the differences (and similarities) between them all.
In the video, Hall goes through the functions of five ranges of heads, points out who they are designed for, and then talks about each of the 17 models Godox produces in all, covering the features each of the heads do and don’t have. He includes an amazing amount of detail and specification, making clear what you get with each model. He even provides a spreadsheet that lists prices, output, recycle times and flash duration, as well as other features and physical characteristics.
The video has information on the DP, SK, QS, GS and QT studio and portable heads, and if you can’t take all the information in quickly enough Hall has written a lot of it in the video’s description.. dpreview.com