Most legacy POS systems our built for desktop computers, and can therefore only be used from a fixed position within a retail space. This is generally an inflexible solution and can contribute to the build up of queues in your shop.
On the other hand, a mPOS or mobile point of sale can used from an iPhone or iPad, which mean sales can be process at any point in your shop. Integrated payments and support for Apple Pay means you can also take payments without being chained to a cash register. This cuts down on queues, and allows for a more flexible and better quality customer experience.