The niyamas are the personal observances, the second of Patañjali's eight limbs. Where the yamas govern how you treat other people, the niyamas govern what you do with yourself. The last three, ardency, self-study, and surrender, are the same three practices Patañjali names as kriyā yoga at the opening of the chapter on practice.
5 Niyamas
saucha (cleanliness)
santosha (contentment)
tapas (ardency)
svādhyāya (self-study)
īśvara-praṇidhāna (surrender to something greater than the ego)