Yama really means abstinence. The yama referred to in the Ashtanga Yoga pertains to ethical observations and mental control. Patanjali enumerates the five important components of yama thus:
i.    Ahimsa (non-violence)
ii.    Satya (truth)
iii.    Asteya (non-stealing)
iv.    Brahmacharya (celibacy or chastity)
v.    Aparigraha (abjuring of possessions)
Though they are laid down as codes of conduct for sadhakas, anyone can adopt these restrictions for the betterment of his or her life.