Differences Between Ring Flash vs Beauty Dish

Some interesting insight into the distinctions between ring/circular highlights.

Ring Light

• Continuos light source
• Donut catchlight

Ring Flash

• Flash based light source
• Halo effect
• Donut catchlight
• Flattens out shadows

Beauty Dish

• Modify's the light source which is the flash
• Loses more light
• Circular catchlight sometimes with a dark center

Source:
Ring flash vs beauty dish?