Platform tokens utilize blockchain infrastructures to deliver decentralized applications (dapps) for different uses. For example, while Dai is categorized as a stablecoin because it is soft-pegged to the US Dollar and its pricing maintained through mechanisms built into smart contracts, it can also be classified as a platform token because it is built on the widely used Ethereum blockchain.
Platform tokens benefit from the blockchains they build upon, gaining enhanced security and the ability to support transactional activity. Platform tokens run the gamut of use cases, from serving gaming and digital collectibles (CryptoKitties!) platforms to global advertising and marketplace industries.