Svastika is derived from su (well), asti (is) and ka (a noun ending). It means "it is well" and hence signifies happiness, pleasure and good luck.
It is a mystic symbol or figure which is sacred to most Indian sects. The symbol is shaped like a Greek cross with the extremities of the four arms bent round in the same direction.
A svastika is of two types: the right-handed or male, representing the vernal sun and the god Ganesha. In this Svastika, the extremities of the arms of the cross bend clockwise. It is considered auspicious.
The left-handed or female cross represents the autumnal sun and the goddess Kali. Its arms are bent in an anti-clockwise direction and it is believed to be inauspicious.
The auspicious symbol is used by the religiously inclined on the opening page of account books. It is also used in ceremonies related to marriage, tonsure, the worship of Lakshmi and during the invocation of the nine planets. It is worshipped as a symbol of the sun, Ganesha and the serpent kingdom.
According to the Vayu Purana, serpents bear the sign of a svastika on their hoods. In festivals and on auspicious occasions, the svastika is drawn on the floor of the house. A yogasana is named after this symbol, and is considered to signify or evoke good luck.
Many theories have been propounded about the svastika. It has been described as the emblem of Zeus, the god of sun, fire and rain, the Trinity and also the Supreme Being, Brahman. Most scholars however regard it as a fire or solar symbol and hence it is called the solar or fire cross. It is believed to be derived from the chakra which is symbolically reduced to four spokes and set at right angles. It also represents the fire-making apparatus of old times, used for kindling the sacrificial fire (homagni). In the Vedas it is referred to as "the wheel of the sun". It indicates cosmic procession and evolution around a fixed centre. It also represents the principle of life and movement that transfers the dwarf to the giant and the microcosm to the macrocosm, named rkvam, the rhythmic movement.
This symbol has been in use since the time of the Indus Valley Civilisation (c. 3000 BC - 700 BC). A large number of seals discovered in Harappa, one of its prime sites, bear svastika designs. Since then, it has represented good luck. Panini, the great Indian scholar, used this symbol as the name of a sign in his grammatical treatise, Ashtadhyayi ("Eight Chapters", 450 BC).
The symbol is not exclusive to India and is known all over the world. Proof of its widespread use has been found in archaeological discoveries in Egypt, China, Greece and Mexico. Curiously, the inauspicious anti-clockwise svastika was used by Hitler as the Nazi emblem.