Fundamentally they are the same, but there are differences:
Shellac is made by CND (Creative Nail Design) where Gelish is made by Hand and Nail Harmony.
With CND Shellac you start off with a base coat, then two to three coats of your preferred colour and a top coat. With Gelish you start off with a Ph Bond, then you apply a Foundation Gel, then two to three coats of your preferred colour and a top coat.
CND Shellac and Gelish are both natural overlays so you apply it on your own nails. CND Shellac calls their product a power polish, which is made from gel and polish and you have to cure it in a UV lamp. Soak off time would be five to seven minutes.
Gelish is a pure gel and you have to cure it in a LED Lamp. Soak off time will be a little longer – ten to fifteen minutes.
CND Shellac is softer on the natural nail and does not require any buffing of the nail during the soak off process.
Gelish is harder on the natural nail and requires buffing of the nail during the soak off process.
CND Shellac can last up to 14 days.
Gelish can last up to 21 days.
Both are amazing products and last longer than a normal manicure.
The nails shine better and you save with having to get a manicure once every two – three weeks.