The term "event" has become overloaded in the computing world. Event streaming, event processing, event messaging, event sourcing, event storming, event-driven architecture, and so on, all represent different aspects of eventful computing. We will examine each of these terms in detail, and explain - with a few illustrated code examples - why these emerging concepts are rising in importance and the problems that they are trying to solve. We will also discuss variations and evolutions of other event-based concepts that are being applied to reactive systems, serverless apps, and stateful as well as stateless microservices. Just like anything, there are also challenges, but the benefits of the event-based approach should outweigh any obstacles in the long run, and will prove itself to be a viable and dynamic solution for today's modern and heavy data-driven systems.