The audit log
The audit log records who did what. Each entry names the person, the action, the resource it affected, and when.
Under the organisation's Audit log. Reading it is gated by the settings permission, so an admin can see it and an ordinary member cannot.
Entries are never removed
The audit log is append-only. There is no way to delete an entry — not from a screen, and not by the application itself.
That is deliberate: a record that can be edited by the people it records is not evidence. If something should not have happened, the log keeps it and records the correction alongside.
Practically, it means the log only grows, and that anything you find in it can be relied on.
Some entries have no organisation
Most entries belong to an organisation. Some — signing in, changing a password, registering — happen to a person rather than within an organisation, so they are recorded without one.
Worth knowing when reading: an account-level event will not appear under an organisation's filter, because it did not happen inside one.
What an entry contains
Who, what, which resource, and when. The action and resource are recorded as the application names them rather than chosen from a fixed list, so the vocabulary grows as the product does.
That means there is no closed catalogue of events to check against — the log tells you what happened in its own terms. See audit log entries for how to read one.
What it is for
Answering "who changed this?" — the common case, usually after something looks wrong.
Showing that a control held. A permission change, a member removal, a role edit: all recorded, so a claim that access was managed properly is checkable rather than asserted.
Reconstructing a sequence. When several things went wrong together, the order they happened in is often the answer.
What it is not
Not a debugging tool. It records deliberate actions, not everything the system did. Background work — the scheduled re-checks, sync jobs — is not the audit log's subject.
Not a substitute for the queues. Failed posts, reconcile reviews and the channel review queue each keep their own history, closer to the work.
Retention
Entries are kept. Nothing in the application removes them, and there is no configurable retention window on the log itself — unlike customer personal data, which is a different mechanism with its own horizon.