This chapter was an introduction to blockchains and, more specifically, to Ethereum. Having a good understanding of the big picture about how blockchains and Ethereum work will go a long way in understanding how to write robust, secure, and cost effective smart contracts using Solidity. This chapter covered the basics of blockchain, explained what blockchains are, why blockchains are important, and how they help in building decentralized and distributed applications. The architecture of Ethereum was discussed in brief along with some of the important concepts such as transactions, blocks, gas, Ether, accounts, cryptography, and mining. This chapter also touched briefly on the topic of smart contracts, using Remix to author smart contracts and how to execute them using Remix itself. I've kept this chapter brief since the rest of the book will explain these concepts further and it will allow you to quickly develop Solidity-based smart contracts.
You'll notice that this chapter does not contain any mention of Ethereum tools and utilities. This is what we will cover in the next chapter, by diving straight in and installing Ethereum and its toolset. The Ethereum ecosystem is quite rich and there are lots of tools. We will cover important ones, such as web3.js, TestRPC, Geth, Mist, and MetaMask.