What's an event?
An event is one instance of you sending us data. Generally, this is an error, but it's possible to send us non-error related data as well.
What's an issue?
An issue is a group of similar events. More details about why certain events are grouped together can be found here: https://docs.sentry.io/learn/rollups/, but most often events are grouped because they’re triggered by the same part of your code, or, if that data isn’t available, because they are exceptions of the same type and value.