A lector is the minister who proclaims the word of God (apart from the Gospels specifically reserved for a deacon or a priest in the absence of a deacon) at mass and other liturgical ceremonies. A lector can be called a reader or a minister of the word.
Apart from proclaiming the word of God, a lector may also lead the faithful in the Psalm when there is no cantor present or in the Prayers of the Faithful in the absence of a deacon The General Instruction of Roman Missal (GIRM), 99).
To proclaim the Word of God during the Eucharistic liturgy.