The first precept (“You shall attend Mass on Sundays and holy days of obligation.") requires the faithful to participate in the Eucharistic celebration when the Christian community gathers together on the day commemorating the Resurrection of the Lord.
The second precept (“You shall confess your sins at least once a year.") ensures preparation for the Eucharist by the reception of the sacrament of reconciliation, which continues Baptism's work of conversion and forgiveness.
The third precept (“You shall humbly receive your Creator in Holy Communion at least during the Easter season.") guarantees as a minimum the reception of the Lord's Body and Blood in connection with the Paschal feasts, the origin and center of the Christian liturgy.
Source: Catechism of the Catholic Church (Vatican.va)