What is the difference between a delegate and an event in C#, and how do you keep event subscriptions from becoming a lifecycle problem?

Multicast delegates invoke handlers in order, and an exception from one handler normally stops later handlers unless the publisher deliberately iterates the invocation list and defines another policy. Return values on multicast delegates are usually a poor event contract because only the last return value is directly observed. For cross-process or durable business events I would not use an in-memory C# event as if it were a message broker. Persistence, retries, ordering, and delivery guarantees need an explicit messaging boundary. In production I would keep events local and narrow, document threading and failure semantics, and verify with heap analysis when a long-lived publisher appears to retain old subscribers.