The Roman Canon is the name given to the Eucharistic Prayer that is presented first in the Roman Missal, the liturgical book used by the priest for the Mass. Until the Novus Ordo, it was the only form of the Eucharistic Prayer to be offered since the 16th Century. However, it has been used, in its current form, since the 7th Century and parts of it go back to the 2nd Century. This is why it remains the most privileged form of the Eucharistic Prayer, although today we are given 4 main forms of the prayer. The different forms are intended to highlight different aspects of the sacred mysteries.