The guru-shishya parampara, the teacher-disciple lineage, is understood in Hindu tradition as the primary vehicle through which spiritual knowledge, particularly knowledge not fully captured in written texts alone, is transmitted from generation to generation, a relationship the tradition treats as considerably more personal and transformative than an ordinary student-teacher relationship in secular education: a guru is traditionally expected to guide a disciple's inner spiritual development directly, often over years or decades of close association, rather than simply conveying information. The Sanskrit term itself is popularly explained, though the etymology is debated among linguists, as combining gu, darkness, and ru, one who dispels, casting the guru as one who removes the disciple's spiritual ignorance.
A guru's authority within Hindu tradition is not conferred by any single centralized ordaining body but is instead recognized informally through a combination of the guru's own demonstrated spiritual attainment, often itself validated by having studied under a recognized guru in an unbroken lineage, and the willing acceptance of disciples who choose to follow that guru's specific teaching and practice; this decentralized structure has historically allowed a very wide range of gurus, teaching styles and specific spiritual paths to coexist within Hinduism without requiring uniform doctrinal agreement among them.