For anyone curious: "c" just means that it's a character device.

There is also "b" for block device (e.g. a disk, a partition, or even something like a loopback device) and "p" for FIFOs (similar to mkfifo).

The two numbers are just identifiers to specify the device, so in case of `5 1` it means the systems tty console, while `1 8` would mean "blocking random byte device" (mknod dev/random c 1 8)