The neutral alignment (sometimes known as true neutral) is without prejudice or compulsion. In 4th edition mechanics for Dungeons & Dragons neutral is found under the umbrella of the unaligned alignment.
A neutral character does what seems to be a good idea. He doesn't feel strongly one way or the other when it comes to good vs. evil or order vs. chaos. He thinks of good as better than evil--after all, he would rather have good neighbors and rulers than evil ones. Still, he isn't personally committed to upholding good in any abstract or universal way.
This is the most common alignment of sentient creatures in the Forgotten Realms and the alignment of almost all animals and other creatures of very low intelligence.
Some neutral characters commit themselves philosophically to neutrality. They are of the true neutral alignment.
A true neutral character sees good, evil, law, and chaos as prejudices and dangerous extremes. He advocates the middle way of neutrality as the best, most balanced road in the long run. His position is carefully neutral, but he does not continually balance his morals in a yin yang or fanatical fashion.
Some true neutral characters actively support balance in the world, and seek to avoid having any one side--law or chaos, good or evil--become too powerful over them or anyone else, and will work against whichever side is the most powerful. They tend to side with the underdog in any situation, and they are often opportunistic in their actions. The epitome of this “militant true neutrality” are the Outlands’ rilmani.
True neutral is committed to the avoidance of extremes, and is non-judgmental.
Nearly all druids are true neutral. The true neutral alignment is central to the philosophy of neutral druids: Because a druid's main charges--plants, animals, and the health of the planetary ecology--essentially lack alignment or ethos, druids feel free to use almost any means necessary to protect them.
The druidic order works to maintain the natural balance among the alignments. However, druids do realize that most individuals' actions--including their own--will prove significant to the cosmic balance. The druid sees the friction between alignments as the driving force in the world.
When faced with a tough decision, a druid usually stands behind the solution that best serves nature in the long run.