I agree with the answer Daniel gave, but I would clarify things slightly differently.
1) Orthodox Judaism believes that the Torah is the literal Word of G-d. This is one of the Thirteen Principles of Faith as brought down by Maimonides:
"We do not know exactly how the Torah was transmitted to Moses. But
when it was transmitted, Moses merely wrote it down like a secretary
taking dictation....[Thus] every verse in the Torah is equally holy,
as they all originate from God, and are all part of God's Torah, which
is perfect, holy and true."
2) The laws of Orthodox Judaism do not however come from reading the text literally, but are interpreted via an oral tradition leading back to Moses (e.g. when it says "An eye for an eye", it actually means monetary compensation, not mutilation).
Again Maimonides (introduction to the Mishneh Torah):
3 But the Commandment, which is the interpretation of the Law--he did
not write it down, but gave orders concerning it to the elders, to
Yehoshua, and to all the rest of Israel, as it is written "all this
word which I command you, that shall ye observe to do . . ."
(Deuteronomy 13,1). For this reason, it is called the Oral Law.
4 Although the Oral Law was not written down, Moshe Our Teacher
taught all of it in his court to the seventy elders; and El`azar,
Pinehas, and Yehoshua, all three received it from Moshe. And to his
student Yehoshua, Moshe Our Teacher passed on the Oral Law and ordered
him concerning it. And so Yehoshua throughout his life taught it
While our understanding of the Torah may have been corrupted over time, Orthodox Judaism holds that the core interpretation of the Torah does not morph to fit the changing notions of morality or modern understanding.
Note that this does not say that bottom line practices cannot change. Consider the analogy of driving a car: Physics says that if you crash into something fast enough you will have a fatal accident, but the legal speed limit is derived by human laws that take the safety of cars and the way people drive into consideration. Thus, the bottom line legal speed limit may change due to scientific advances (safer cars) and social norms, but the physics of it is still immutable.
3) Finally, regarding things like evolution/creation, etc. Orthodox Judaism generally has quite the open mind. As long as there is no impact on the core interpretation of the Torah, then any amount of allegorical understanding is valid.
Maimonides (intro to Perek Helek):
It is often difficult for us to interpret words and to educe their
true meaning from the form in which they are contained so that their
real inner meaning conforms to reason and corresponds with
truth......when you encounter a word of the sages which seems to
conflict with reason, you will pause, consider it, and realize that
this utterance must be a riddle or a parable. You will sleep on it,
trying anxiously to grasp its logic and its expression, so that you
may find its genuine intellectual intention and lay hold of a direct
faith, as Scripture says: “To find out words of delight, and that
which was written uprightly, even words of truth”
Now technically Maimonides is addressing here the words of the Sages, not the actual Torah. Still this is completely in line with his understanding of (e.g.) the story of Creation in his "Guide to the Perplexed", and I would argue what most Orthodox Jews follow.
Final note. Maimonides is not the end-all answer for what Orthodox Judaism believes (there were considerable debates even in his day), but his writing are generally considered to be one of the pillars of our understanding.