In Indian religions and society, an acharya is a preceptor and expert instructor in matters such as religion, or any other subject. An acharya is a highly learned person with a title affixed to the names of learned subject. The designation has different meanings in Hinduism, Buddhism and secular contexts.

Guru is a Sanskrit term for a "mentor, guide, expert, or master" of certain knowledge or field. In pan-Indian traditions, a guru is more than a teacher: traditionally, the guru is a reverential figure to the disciple or student, with the guru serving as a "counselor, who helps mold values, shares experiential knowledge as much as literal knowledge, an exemplar in life, an inspirational source and who helps in the spiritual evolution of a student". Whatever language it is written in, Judith Simmer-Brown says that a tantric spiritual text is often codified in an obscure twilight language so that it cannot be understood by anyone without the verbal explanation of a qualified teacher, the guru. A guru is also one's spiritual guide, who helps one to discover the same potentialities that the guru has already realized.