@feruze-- Literal truth defense is when a defendant gives answers that are "literally true" but conceals another piece of information at the same time.
A super simple example would be if you asked a defendant if he has apples and he tells you that he has pears. The defendant has not lied here because he really does have pears, but he has apples too! So he is answering in a way that hides the truth or avoids saying it, so to speak.
It's true that you can give the literal truth in court but it doesn't always mean that it will protect you from perjury. I have heard of several cases where literal truth statements were still considered as perjury and those people were sentenced. It might be a good idea to check court practices and case examples in your particular state. I think there are some variations from state to state.