Things may go wrong. It’s computers, after all. If a log exists, developers and/or users have a chance of figuring out what happened, and fix whatever the problem was. Without such logs, life can be very frustrating. So, let’s log!
Analyzing what happened on a user’s device is easier if all code on that device uses single logging facility. If a problem occurs due to an unexpected interaction between two different components, for example, a single log has all events in chronological sequence and debugging is much easier.
You can find a few excellent introductions to logging via systemd on-line, e.g.
For general information about systemd, see the Systemd home page.
When logging, developers are encouraged to provide as much contextual information as needed to understanding the context of the message, in particular the AppConfigId of the installation that the log message refers to. The syslog identifier should be set to the name of the reporting package.