The word ‘Catholic’ means welcoming all comers from all cultures and social strata. No one description or model can cover the richness that is the Church. In recent times theologians have coined three terms to try to capture this richness.
The first is ‘the people of God.’ It covers the visible communities and the governing structures holding all believers together from the pope to the newest baptised baby.
The Church is also 'mystery and sacrament’.
It has a unique relationship with God, being the image and body of Christ in the world by the power of its prayer and sacraments, a revelation of God’s love present and active among us.
Finally the Church is ‘Communion and Fellowship’, a community of people who share in belief and love, united in a common faith that bridges different languages, cultures and social classes.
At its best the Church is the face of God ever present in a constantly shifting and changing world. This is most evident in the Catholic Mass where all believers come together to share the consecrated bread and wine which makes them one with Jesus and one another.
Source: Catholic DiscoveryOur Catholic World