Bernafon and Dynamo are from the same company but different as Rasmus Points out. Bernafon is sold in Europe and Canada but not really found in the US except at Costco.
Resound is another manufacturer with their own hardware and software.
With all brands having their own approach, each will have its adherents who feel that aid reproduces sound best for their situation.
Names change with every new product line to confuse the users. And there can be other names/brands that are closely link to a manufacturers line either through franchises or other wholesalers.
To make it more confusing, each product name may have a number of iteration levels with have different feature enabled or disabled. It is the same hardware and software typically. They just disable features to produce the "low price" version. This is most often three levels. You might see one clinic quote $3200, 4800, 6200. An online seller may be 1-2k less across such pricing.
OK, are you confused? Then good; that's what all the above intends.
Your decision should be based on your hearing loss and lifestyle. Too many new users feel that if it cost more it is better. It will have more features but do you need them? You are the only one that can decide and that is done through trials. If you have a mild loss and aren't having a lot of problem in a noisy setting, the "bargain" version is a good starting trial point.