What Does It Mean?

You are correct!

From our dictionary:
tau•tol•o•gy

(tô•tol'u•jE),
n.,
pl. -gies.

1. needless repetition of an idea, esp. in words other than those of the immediate context, without imparting additional force or clearness, as in "widow woman."
2. an instance of such repetition.
3. Logic.
a. a compound propositional form all of whose instances are true, as "A or not A."
b. an instance of such a form, as "This candidate will win or will not win."