Phoenix LiveView is an innovative tool for building interactive, real-time applications without dealing with client-side complexity. It allows developers to write dynamic server-rendered applications without writing JavaScript and offers features such as real-time validations on forms or updating the quantity in a shopping cart. The technology started with a simple itch - wanting to write dynamic server-rendered applications without writing JavaScript, and has evolved into a powerful tool for building dynamic applications. It provides optimizations like minimal diffs, best-in-class payloads, lazy loading, and bundle splitting without the need for complex configuration or build tools.