Signs and symbols
Inasmuch as they are creatures, these perceptible realities can become means of expressing the action of God who sanctifies men, and the action of men who offer worship to God. The same is true of signs and symbols taken from the social life of man: washing and anointing, breaking bread and sharing the cup can express the sanctifying presence of God and man's gratitude toward his Creator.
Source: Catechism of the Catholic Church (Vatican.va)