It is recommended to use original compatible charger to charge a laptop. Non original chargers are often cheaper. Their voltage and amperage can be the same as in case of original charger, so theoretically they should work without problems.
But from my experience I don't recommend to use non original chargers, because after I have started to use one, multiple problems with laptop's hardware have occurred in a short period of time. It is difficult to prove a relation between using of non original charger and hardware problems, but I have heard about multiple similar cases.
Because there are many alternative charger manufacturers, the quality of available non original chargers is not the same for each device. I would say that using of non original charger to charge your laptop is risky.