Father Deo Blessing the People.
The baptismal focus of holy water is clearest at the Easter Vigil, where the sprinkling is directly connected to the renewal of baptismal promises. The Easter Vigil is a proclamation of the presence of the risen Christ among us. The Easter Vigil not only proclaims our faith in the Resurrection, but also our belief that Christ is among us today.
During the Easter Vigil, after the proclamation of the readings, a procession to the font forms. There, the priest blesses the water. If there are catechumens or infants, the Rite of Baptism follows. The catechumens, as well as the parents and godparents of the infants, make the renunciations as a group (e.g., “Do you renounce . . . ?”). Parents and godparents of infants may also respond as a group to the questions professing faith (e.g. “Do you believe in God . . . ?”), but catechumens answer this second set of questions individually.
The adults and infants are baptized and receive a white garment and a glowing candle. Adults and children of catechetical age are then confirmed on the forehead. Infants are anointed with chrism on the crown of the head, as they are when the Rite of Baptism for Children takes place at any other time of year. (If there are no catechumens or infants for Baptism, these ceremonies, obviously, are omitted.) After the anointing, the priest invites the people to renew their baptismal promises and sprinkles them with holy water.
http://www.pastoralliturgy.org/resources/0703WaterAndPromises.php