A runlevel is a software configuration of the system that
allows only a selected group of processes to exist. Init can run the
system in one of eight runlevels. The main runlevels are 0-6. The
system runs in only one of these runlevels at a time. Typically these
runlevels are used for different purposes. Run level 5 is X11.
If you don't want to boot into the UI use runlevel 3.
Hit a key when you get the booting....message, then hit "a" to append
to the command line. Then add"3". This will boot into runlevel 3
and should put you at a text-based prompt to login.