Similar to Link, the protagonist of the series, Zelda has had many incarnations throughout the series. Princess Zelda has been depicted at various ages depending upon which title she appears in. She has appeared as child, a teenager, and as a young adult; for example, Princess Zelda in Twilight Princess is around 20 years of age.
Early on in the legend, Zelda, while born as human, becomes the mortal incarnation of the Goddess Hylia. Carrying on this devine blood, Zelda is invariably the crown princess of Hyrule in whichever time period she appears. She is also the possessor of the Triforce of Wisdom, imbued with the essence of the Goddess Nayru. The essence of Nayru affords Zelda divine wisdom, allowing her to discern the wisest decisions, especially in situations concerning the welfare of Hyrule. It also grants her a myriad of mystical abilities, including the ability to heal others.
Zelda is depicted as a kind and benevolent ruler with a wisdom beyond her years and a deep love towards the people she watches over. She is a caring, graceful and self-sacrificing person. Zelda's most prominent display of compassion and selflessness was when she saved the life of Midna, the Princess of the Twilight Realm, who had been nearly killed by the false King of the Twilight, Zant. Zelda's wisdom is her most valuable attribute. As a matriarch, it is imperative that she make the wisest decision concerning the fate of Hyrule; in Twilight Princess when Zant threatened her life and the lives of all of her subjects, she wisely surrendered to him. Above all, Zelda is known to be a forgiving person even towards those who have harmed her before, as seen in Spirit Tracks, where she asks Anjean to take care of Byrne even though he was the one who stole her body.
Princess Zelda is one of the three most important characters of The Legend of Zelda series, which is also why her name appears in the title of every game. Princess Zelda first appeared in the original The Legend of Zelda, and has since been featured in every subsequent game, with the exception of Link's Awakening. Each Princess is chosen by destiny to be the keeper of the Triforce of Wisdom in their era, which is the main reason why they play such an integral role in the legends of Hyrule.
Throughout the history of Hyrule, there have been several ancestors and descendants bearing the name Princess Zelda. It has so far become unclear as to which princess was the first to bear the name, although many suspect it to be the Princess Zelda of Skyward Sword since it takes place before Ocarina of Time and is thus first in the timeline.
Throughout the series, Princess Zelda portrays various types of both magical and physical abilities, ranging from capably wielding a bow to telepathy, as seen in A Link to the Past's introduction when she pleads for Link's help. Many of her abilities as both a Sage and the wielder of the Triforce of Wisdom are widely illustrated in Ocarina of Time, one of them being that she has prophetic visions in her dreams. She also helps Link in their escape from Ganon's Castle by using her powers to magically remove the barriers blocking the exits. During the final battle between Link and Ganon, Princess Zelda uses her powers to restrain the King of Evil as Link delivers the final blow. Being the seventh Sage, she is the ruler of the rest of the six Sages, and it is with her guidance that the Sages seal Ganon in the void of the Evil Realm. Finally, with her powers as a Sage, she is capable of returning Link to his original time by simply using the Ocarina of Time.
Some of Princess Zelda's physical abilities are demonstrated in games such as The Wind Waker, Twilight Princess and Spirit Tracks. In The Wind Waker, Princess Zelda aids Link in battling Ganondorf by borrowing the young hero's bow and using it to fire Light Arrows at the King of the Gerudo. This skill is again portrayed in the final battle of Twilight Princess, where the princess yet again uses a bow and Light Arrows to strike Ganondorf while accompanying Link on his horse, and once more in the final battle against Malladus in Spirit Tracks. In one scene of Twilight Princess, Princess Zelda is seen wielding a sword, although it is unknown whether she possessed any true sword skills.
As shown in Twilight Princess, Princess Zelda is capable of communicating with the Light Spirits. Just as the princess and Link are about to be attacked by Ganondorf's ghostly army, Zelda calls upon the Light Spirits to aid her in her time of need, in which the spirits grant her the Light Arrow to banish evil.
In Spirit Tracks, Princess Zelda can possess a Phantom's body after Link strikes it with a powered-up sword or the Lokomo Sword. While in this state, the princess can help out Link solve various puzzles as well as cross certain obstacles that the young hero cannot do by himself. Moreover, due to the Phantom's armor, she can also protect Link from attacks or use her strength to fight alongside Link and help him defeat enemies, as seen when fighting Geozards or Byrne.