In the preceding chapters, you designed and developed the core component of a blockchain application: the smart contract. But the logic coded in a smart contract cannot act alone. You need user-facing applications that will trigger the smart contract functions and blockchain services. These applications invoke smart contract functions, which in turn verify, validate, and record the resulting transactions and data on the distributed ledger of the blockchain. In this chapter, you’ll learn about the structure of this larger system, called a decentralized application (Dapp), and explore the techniques and tools for developing Dapps. Recall the Dapp stack and the definition of a Dapp from chapter 1, shown in figure 4.1.
