Tchaj-ťi tchu (taijitu) – symbol jin a jang

Taijitu – the yin-yang symbol

Balance / harmony

Taichi (taiji) energy in a state of harmony and balance, evenly melting into one another and mutually supporting each other´s distinct forces.

Nowadays probably the most common, simplified variation of the yin-yang symbol – opposites existing in complete harmony. These two (black and white) seemingly opposing, but complementary halves make a whole and thus, whithout each other, are incomplete. Together they form a perfect circle.

Movement /stillness

Taichi (taiji) energy in a state of acceleration, causing the center to slow down, condense and become still, while the outside is in continuous motion. Yin and yang rotate, while the core reverts to stillness – wuchi (wuji).

The central circle represents wuchi (wuji), nothingness/void, from which taichi (taiji) emerges and then returns. This vision of the diagram also emphasises the spiralling nature of energy.

This variation of the yin-yang symbol is allegedly attributed to a Ming period Neo-confucian philosopher Lai Zhide (1525–1604). Yet another source says the author is a Sung dynasty (AD 960–1279) metaphysician called Lai.   

Building / storing

Taichi (taiji) energy in  state of opposition and struggle, separately building and storing power, yet still remaining connected and unified.

Another fairly rare version of the yin-yang is one that uses concentric circles divided in half and alternating black and white to each side.

Some versions also have the centre circle split between black and white, whilst other versions keep this blank and so representing the pure seed from which all of creation is born. Where five concentric circles surround the inner circle – this can be seen as the manifestation of the five elements (Earth, Metal, Water, Wood and Fire), each with their yin and yang aspects.

Source:
Ancient Symols.com
Pennine Taichi
Wikipedia