Gifts are mystical tricks bestowed by spirits to an Uratha, unusual magical abilities that draw on a werewolf's half-spirit nature to accomplish things that would otherwise be impossible. They are not spells or innate abilities. They're more like a spirit's Numina. Individual Gifts are frequently limited in effect, but the sheer variety of Gifts that spirits are capable of teaching grants werewolves a versatile array of power.
Spirits don't hand out Gifts for free, though. Nothing comes for free in the spirit world, particularly to the Uratha. A werewolf must somehow appease one of these hostile entities, even one that is ordinarily a friend to her totem, before it agrees to bless her with a Gift. Even if a spirit were to be greatly fond of a werewolf (or in love with her, as legends sometimes speak of), it couldn't give her something without asking for something in return. It is one of the laws of the next world. The spirit may ask for little in return if it feels charitable (unlikely), or it might ask for the near impossible if it dislikes the werewolf (sadly likely). In any event, learning a Gift is more a matter of negotiation and making offerings than of study and practice.
As of 'Werewolf the Forsaken Second Edition, the structure of Gifts are getting a major reorganization. (Source: http://theonyxpath.com/gifts/)
- Moon Gifts replace Auspice Gifts, with each Auspice having one. Facets are tiered from one dot to five dots, and are gained for free every time the werewolf buys a dot of her Auspice Renown.
- Shadow Gifts do not have dots, and instead each Gift is divided into five Facets that correspond with a Renown. Buying a dot of Renown gives a free Facet of a known Shadow Gift. A Shadow Gift Facet can still be bought with Experiences, but characters can’t have a Shadow Gift Facet that they don’t have any dots in the Renown for. Shadow Gifts themselves can still be bought in with Experiences.
- Wolf Gifts work like Shadow Gifts, but characters don’t have to buy in to them. Characters can take Facets with Renown or with Experiences.