The derma roller is a less sophisticated version of the derma pens. The derma roller has fixed needle depth attachments and is hand operated. However, you can still achieve amazing results.
The derma pens are motorised, have adjustable needle depths and speeds, rechargeable batteries, a selection of cartridges including options of finer or thicker needles, different options for the number of needles and are made from superior materials.
If you are unsure about microneedling, the derma roller is a more cost effective, easy to use option for beginners.