This document provides an introduction to blockchain technology and its potential applications in digital advertising. It explains key concepts such as what a blockchain is, how it uses cryptography and hash functions to securely store data in blocks, and how the linking of blocks through previous hashes makes the blockchain immutable and resistant to change. The document demonstrates how to build a sample blockchain and discusses how the decentralized nature of blockchains achieves consensus without the need for a central authority. It concludes by outlining the agenda for a blockchain bootcamp focused on use cases for advertisers and publishers.