ahimsa harmlessness, non-violence
satya real, genuine, honest, virtuous, truthful
asteya non-stealing, non-misappropriating
brahmacarya continence, chastity, religious studentship
aparigrahah without possessions, without belongings, non-acceptance of gifts
Non-violence, truth, abstention from stealing, continence, and absence of greed for possessions beyond one's need are the five pillars of yama.
The principle of yama involves wishing no harm in word, thought or deed; being sincere, truthful and honest; not stealing or misappropriating another's wealth or possessions; celibacy; and not accepting gifts or possessing only what one needs, without being avaricious.
These rules and restraints are laid down clearly for one to live in society while remaining a yoga practician.