Pinking shears are scissors with an blade that is spiked instead of straight across like a regular pair. Pinking sheers are used to finish off fabric that does not necessarily need a strong hem. They can be used for any type of material that will not unravel - such as silk or charmeuse. This tutorial from Threadbanger will show you how to finish off your fabric by pinking, which is actually incredibly simple to do.
Remember! Never use your fabric scissors on paper.