Celtic designs are rich in history and possess a number of different meanings. Much of what is known about Celtic symbolism is conjecture due to the fact that few written records survived into the modern age.
Popular symbols of Celtic culture include the triskelion, the triquetra, spirals, triple rays, the three-fold, the five-fold and a variety of knots and crosses. According to What's Your Sign, the triskelion means "three legged," which is an apt name for a symbol composed of three connected branches. The triskelion represents competition and progress. The triquetra features three interconnected petal shapes that represent the trinity.
The spiral represents the radiation of energy in or out, and it symbolizes growth, birth and expansion of consciousness. The double spiral symbolizes balance. The triple spiral represents female power through transition and growth. Each spiral represents the maiden, mother and crone, respectively.
The three rays are similar in meaning to the Chinese yin-yang. The first and third rays represent man and woman, and the middle ray represents the balance between the two. The three-fold is much like the triquetra and also represents the trinity. Balance between the elements of earth, water, fire and air is represented by the five-fold.
Symbol Dictionary indicates that Celtic knots can represent infinity, interconnectedness and rebirth. Finally, the Celtic cross represents the passage between heaven and earth, with the ringed cross symbolizing eternal spiritual love. Many Celtic crosses are also adorned with patterns of Celtic knots.