Victor is talking about the new abilities in the Type a Keystroke to press and hold a key.
A normal keystroke involves pressing and releasing the key.
You can Press and Hold or Press and Repeat, either of which result in the key being held down and the macro continuing. The difference is with Press and Repeat, the key is held down and periodically released and repressed, just as happens if you press and hold a repeating key on the keyboard.
Either way, you can later release the key using a copy of the action with the Release option. Or once the macro completes, the key is automatically released.