NEM is built from scratch as a powerful and streamlined platform for application developers of all kinds, not just as a digital currency. Using NEM in your application is as simple as making RESTful JSON API calls allowing you to configure your own "Smart Assets" and make use of NEM's powerful blockchain platform as your fast, secure and scalable solution. XEM is the underlying crypto currency of the NEM network. It is used as instant payment around the world. It also can be used to pay for transfer fee, coin issue, crypto info and other features.