Which one is the 'real' one?
I currently know 5 diatonic scale patterns. Using one of those 5 patterns, a C-major scale can be played anywhere up and down the neck; which pattern you use depends on where on the neck you want to play it. I also can use 3 different patterns to play a C-major scale along the neck. The multitude of ways that you can finger a sequence of notes on the fretboard seems to be what's causing you confusion.
So, pick a convenient spot on the neck where you happen to know that a C lives (low E string, 8th fret for instance), and then pick what finger you want to start with (let's say middle). Put your middle finger on that C, and then play the natural notes that fall under your fingers: C (low E string, middle finger), D (same string, pinky), E (5th string, index finger), F (5th string, middle finger), G (5th string pinky), A (4th string, index), B (4th string ring finger), C (4th string, pinky), D (3rd string, index), E (3rd string, ring), F (3rd string pinky), G (2nd string, middle), A (2nd string pinky), B (1st string, index), and back to C again (1st string, middle). Then start at the bottom, and play the sequence in reverse, just for practice.
Congratulations, you've just played one of the many C major scales that exist on the neck!
If you draw a picture of the neck with all the frets and strings, and where all the natural notes are, you can figure out where you can do this sort of thing. Customarily, the major scales begin and end with the root note; if you start playing the scale on some other note, you're getting into a different 'mode', and your teacher may scold you for it.
Good luck!
edit: Darnit, Zurf beat me, too!
"There's such a fine line between genius and stupidity."
--David St. Hubbins
