The document discusses mobile wallets, which are electronic accounts held on mobile phones that can store and transfer currency value. It describes the mobile wallet ecosystem, which includes services that enable and support mobile wallets. This ecosystem includes issuing banks, payment networks, acquiring banks, hardware providers, software providers, mobile carriers, merchants and point of sale providers. The document outlines the different types of users in the mobile wallet system, including buyers and sellers, and discusses several examples of existing mobile wallets like Google Wallet, PayPal, Square Wallet, Level Up and ISIS. It also covers how mobile wallets make money and highlights user concerns about security and complexity.