When you login over ssh, the message of the day (motd) is displayed.
On a default Debian installation, it looks like this:
Linux T450s 4.19.0-6-amd64 #1 SMP Debian 4.19.67-2+deb10u2 (2019-11-11) x86_64 The programs included with the Debian GNU/Linux system are free software; the exact distribution terms for each program are described in the individual files in /usr/share/doc/*/copyright. Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent permitted by applicable law. Last login: Sun Jan 12 12:16:15 2020 from ::1
The motd can easily be extended with useful information
by placing some scripts in /etc/update-motd.d/.
With additional scripts in place, it could look like this:
Linux T450s 4.19.0-6-amd64 #1 SMP Debian 4.19.67-2+deb10u2 (2019-11-11) x86_64 System information as of Sun 2020-01-12 12:59:54 CET System load: 0.69 Processes: 180 Usage of /: 12% of 118G Users: 3 Memory usage: 10.2% System uptime: 1:14 hours Swap usage: 0.0% IP of wlp3s0: 192.168.0.123 Temp of acpitz: 49.0°C *** System restart required *** The programs included with the Debian GNU/Linux system are free software; the exact distribution terms for each program are described in the individual files in /usr/share/doc/*/copyright. Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent permitted by applicable law. Last login: Sun Jan 12 12:16:15 2020 from ::1