The two-part framework of varna, four social categories, and ashrama, four life stages, described in the Gita and elaborated further in the Manusmriti.
वैदिक व स्मृति साहित्य · Vedic & Smriti literature
The Bhagavad Gita (4.13) describes the four varnas, Brahmin (teachers and priests), Kshatriya (rulers and warriors), Vaishya (traders and farmers), and Shudra (laborers and service providers), as created according to guna and karma, quality and action. The Manusmriti, covered on this site alongside this page, elaborates the specific duties, dharma, expected of each varna in far greater detail.
Ashrama divides an individual life into four stages regardless of varna: Brahmacharya (student life, celibate study), Grihastha (householder life, marriage and family), Vanaprastha (gradual withdrawal from worldly responsibility), and Sannyasa (renunciation). This life-stage framework remains widely referenced today, describing a life's arc from learning through responsibility to eventual release rather than assigning fixed social status.