The five observances listed - purity (Shaucha), contentment (Santosha), austerity (Tapas), study (Svadhyaya), and surrender to God (Ishvara Pranidhana) - are the Niyamas, the second limb of Ashtanga Yoga. Yamas are the five restraints (social ethics), while Dharana and Samadhi are the 6th and 8th limbs respectively.