Five animals (sheep, goat, cattle, water buffalo, camel) that are sacrificed to gain the blessing of and to become closer to Allah (s.w.t) on the days of Eid-ul Adha are called Qurbani.
According to Hanafi Fiqh it is Wajib upon every Muslim who has the wealth equal to the Nisaab to sacrifice a Qurbani once a year on Eid-ul Adha.
THE NISÂB AND WUJUB OF UDHIYYAH (QURBANI)
The Nisâb of Udhiyyah is to be in possession of an amount of wealth which renders Sadaqah Al-Fitrah to be Wâjib. It is Wâjib upon every male and female Muslims who are free and Muqim (resident) to offer sacrifice if they possess this amount of Nisab.
Unlike in the case of Zakah, it is not necessary that this amount be in one’s possession for a complete lunar year and it has the potential to grow.
Basic and Essential Necessities: A house, sufficient amount of its furniture, a car, three types of clothing, -like work outfits, casual clothes and occasion wear- and an income for the person himself and his dependents, which is sufficient to sustain their livelihood for a complete lunar year. One who is in possession of 80.14gr of gold or its equivalent in money, or any other form of wealth which is surplus to the previously mentioned necessities, is obliged to practice Udhiyya once a year.
If a person possesses such an amount of wealth towards the end of the prescribed time for sacrifice (12th of Dhul-Hijjah for Hanafis and 13th of Dhul-Hijjah for Shafiis), offering Udhiyyah will immediately be Wâjib (incumbent) on him.
Free and Muqîm (resident) Muslims, who are in possession of the Nisâb amount of wealth, are recommended to offer sacrifice on behalf of their young children. This is Mustahab (recommended). The rule is mentioned like that in Zâhir Al-Riwâyah and the fatwâ (ruling) is passed accordingly. However, according to the narration of Imâm Hasan (rahmatullâhi alayhi), which he reports from Imâm Abu Hanifah (r.a.); it is Wâjib (incumbent) to offer Udhiyyah for his young children and grandchildren who have no parents. Imâm Quduri (r.a.) preferred the narration of Imâm Hasan (r.a.) in this regard.
According to Imâm Azam (r.a.) and Abû Yûsuf (r.a.), sanity and bulûgh (age of puberty) are not among the conditions of being liable for the sacrifice. Parents or guardians of the insane and the children under the age of bulûgh can do the Udhiyyah from their possessions, on their behalf, and feed them with the meat. The remainder of the meat can be exchanged for some necessities which can be used, such as clothing. However, sanity and bulûgh (age of puberty) are among the conditions of being liable for the sacrifice according to Imam Muhammad.