Replays
The same recording, with the controls back.
A replay is the same content, watched on the attendee's terms. The player has its controls back, so they can pause, rewind and skip.
Replay views are counted separately from attendance, so you can tell the difference between someone who came to the session and someone who caught up later.
Steps
Use the replay link
Each registrant has their own, available as {replay_url} in your emails. It is their watch link in replay mode, so views are still attributed to them.
Send it to the people who need it
No-shows are the obvious audience. So are partial attendees — they have already shown interest and know what they missed.
Let the ended page offer it
Anyone arriving at a finished webinar is shown an ended page that offers the replay where one exists, so a late click on an old link is not wasted.
Result
Attendees who missed the session can still watch it, and you can see who did. Replay views and the time of the most recent one are both recorded against the registrant.
A live webinar's replay is its recording — which exists only if the recording was made, so it is worth confirming one is there before promising it.
Troubleshooting
A live webinar's replay comes from its recording. If the recording was not made, there is nothing to replay — and that failure is not shown on screen at the time, so check rather than assume.
That is the position being remembered from an earlier visit. The controls are available in replay mode, so the viewer can go back to the start themselves.