Some authors use the word "console" to refer to the keyboard and monitor that are attached to the system unit. This is described as a "physical console" by some Linux documentation. The console where system messages appear is described as the "logical console" by that documentation.
As an illustration of the difference, X Windows should start on the physical console but system messages issued by failures when starting X Windows should be written to the logical console.
To avoid confusion this HOWTO uses the word "console" to describe the place where system messages are printed. This HOWTO uses the phrase "attached monitor and keyboard" rather than the confusing words "physical console".
These distinctions are also made in the naming of devices. The device /dev/console is used to send messages to the console. The symbolic link /dev/systty points to the device which is used by the attached monitor and keyboard, often /dev/tty0.