There are many kinds of events:

• In common language, an event is something that happens (changes). An event can be significant - such as a major football match or an earthquake - or it can be insignificant - such as one raindrop making a ripple on a pond during a storm. An event is anything that happens. The likelihood of an event being significant is approximated by Weinberg's Law of Twins.
• In information processing, an event is a change in the properties received by an observer after being transmitted from an object.
• In physics (and in some kinds of philosophy), an event occurs at a point in time which can be distinguished because the state of the world changed. Something was different before and after the event. Physics also speaks of event horizons and simultaneity. In Physics and in Science in general, an event may be contrasted with a process, which occurs across intervals, not just at a point on a timeline. An action or relationship may be misunderstood when viewed as an event or single point of focus. Instead, it may help to view it as part of an integrated process.
• In special relativity (and general relativity), an event is a point in the spacetime continuum, i.e. it has a position in space and time.
• In probability a possible outcome of an experiment is called an elementary event, while a set of those (a subset of all) is called simply an event (see event (probability theory)).
• In biology one speaks of extinction events
• In computer science, an event is a software message that indicates something has happened. See event-driven programming. A number of protocols, such as MIDI, are also event-based.
• In philosophy, one might want to distinguish facts from events, and then between physical events, mental events, and brain events.
• Many athletic functions are called events. See, e.g., middle distance track event.
• In life in general, something required of us may be overwhelming when viewed as an event, but becomes very manageable when broken up into bite sized pieces of a sequential process.