They are called a laymen who have been trained and appointed by their bishop to help a priest distribute Holy Communion at Mass or to carry the Eucharist to the sick or shut ins. They are normally called and Extraordinary Minister of the Eucharist.
An extraordinary minister of the Eucharist helps distribute communion at Mass and also may take communion to the shut-ins, sick and dying. With permission, in areas lacking in ordained clergy, he/she may also conduct a Communion Service, exercise the ministry of the word, preside over liturgical services and confer Baptism.
(Canon Law 230.3)
Usually one must be at least 18 years of age to become a Eucharistic minister, have the permission or recommendation of your pastor or youth minister and be willing to undergo training.
the priest or eucharistic minister
Yes, you must be a Catholic.
The eucharistic minister says, "the body of Christ." and you say "Amen."
A bishop, priest, deacon, or Eucharistic minister.
Yes, they can.
A priest, deacon or Eucharistic minister may apply ashes on Ash Wednesday
No, a Eucharistic Minister may not refuse communion to anyone with the possible exception of very young children who have obviously not made their First Communion.
Catholics do not TAKE Holy Communion, they may only RECEIVE it from a priest or a licensed Eucharistic Minister.
The usual minister for a parish is a priest or bishop. In rare cases where there is a shortage of priests, a deacon or even lay Eucharistic minister may lead a prayer service and distribute communion that has been previously consecrated at a Mass by a priest.
The General Instruction of the Roman Missal, No. 160 "When receiving Holy Communion, the communicant bows his or her head before the Sacrament as a gesture of reverence and receives the Body of the Lord from the minister. The consecrated host may be received either on the tongue or in the hand, at the discretion of each communicant. When Holy Communion is received under both kinds, the sign of reverence is also made before receiving the Precious Blood." The bow is not to the minister (or Priest) rather it is to the Body or Blood of Christ. So yes you bow regardless of who is the Eucharistic Minister.
The ordained ministries in the Catholic Church are deacons, priests and bishops. There are also other extraordinary ministers but they are not ordained. Am example would be a Eucharistic minister.