Which user(s) are logged in to the system. What are they doing?

$ w
 19:16:16 up 1 day,  3:17,  2 users,  load average: 0.27, 0.23, 0.17
USER     TTY      FROM             LOGIN@   IDLE   JCPU   PCPU WHAT
vagrant  pts/1    10.0.2.2:S.0     19:15    1.00s  0.03s  0.00s w
vagrant  pts/2    10.0.2.2:S.1     19:16    9.00s  0.06s  0.03s vim a.txt