last
Reading the systemPackage: util-linux
Recent logins and reboots, read from wtmp. It dates a reboot without a trawl through the journal, and shows who was logged in when an incident happened.
What its options do in the lessons
From the same glossary the lessons render under their commands, so the two cannot disagree.
last -a- Puts the hostname in the last column, which keeps it readable when it is long.
Lessons that teach it
No lesson names it among its useful commands; it appears inside other lessons' command lines.