当我运行w- 查看谁登录以及他们在做什么时，我看到：
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
user tty7 :0 08:14 10:32m 44:10 0.50s gnome-session
user pts/0 :0.0 09:15 9:30m 0.24s 0.24s /bin/bash
user pts/1 :0.0 14:14 4:32m 0.20s 0.20s bash
user pts/5 :0.0 18:27 9:24 0.28s 0.28s bash
user pts/7 :0.0 18:35 9:57 0.40s 0.40s bash
user pts/8 :0.0 18:37 0.00s 0.22s 0.00s w
是什么pts/？