The Primary Format of Liturgies

There are seven different hours that would begin with the Office of Readings or Matins. The first one in the morning is called Lauds, which means praise or morning prayer. There's a mid-morning prayer, mid-day, mid-afternoon prayer and then there's an evening prayer called Vespers and night prayer, Compline. And more or less, every three hours then, the church comes together to pray. So what's the primary format of liturgy hours as opposed to liturgies of the mass? Why do we have a variation of liturgies?" "The heart of the liturgical day is the eucharistic representation of the Paschal