The Night Elves of Kalimdor are a mighty race that emphasizes mobility, ranged firepower, and spellcraft. They do not have the brute strength of other races, but their skills with bow and magic more than compensate for this deficiency.
Advantages

Ancients
Several buildings of the Night Elves are actually sentient trees that can move. They are the Tree of Life, Tree of Ages, Tree of Eternity, Ancient of War, Ancient of Wind, Ancient of Lore, and Ancient Protector. These buildings can be uprooted with the Uproot command, and moved around at will. When walking they can attack land units, but they cannot engage in their normal activities, such as receiving resources or creating units. To return to building form, they must re-root themselves. All Ancients have the Eat Tree ability. Ancients can benefit from the following abilities: Eat Tree: If damaged, Ancients can consume trees to regain health. Nature's Blessing: This ability is researched at the Tree of Eternity, and once completed improves the movement speed and armor of Ancients.

Shadowmeld
Night Elf females possess the Shadowmeld ability. This enables them to turn invisible when they are not moving or attacking. The Archer, Huntress, and Priestess of the Moon all possess this ability. To force these units to remain motionless, even when enemy units would otherwise provoke response, you may use the Hide button. Shadowmeld only operates during nighttime. Hide: Force your units to remain motionless; units will not attack when hidden.

Enhanced Night Vision
Night Elves can be upgraded to see as adeptly in darkness as they do in daylight. This ability is called Ultravision, and is researched at the Hunter's Hall.

Moon Wells
The Moon Wells of the Night Elves, in addition to providing food, have mana reserves that can be used to restore the hit points and mana of nearby Night Elf units. Mana spent in this way slowly regenerates, but only at nighttime.

Night Elves do not use up trees when they harvest them allowing Wisps to stay in place wherever you send them.

Night Elves are very effective against air units with Archers.