There are two types of neutrality. Both choices sit between the extremes on their alignment axis. This could mean that the character has no interest in those matters, that the character is actively trying to oppose both, or that the character is trying to maintain some form of balance in power.
Those who are Neutral as regards Good and Evil, "are committed to others by personal relationships". Meaning that they do not see morality in terms of actions (such as "stealing is wrong") but rather see morality in terms of loyalty to personal relationships. So they may, for example, see stealing from the family or clan as wrong (because it is a betrayal of those personal relationships) but would not see stealing as inherently wrong (you can steal from strangers).
A character who is neutral on both axis is considered to be true neutral.