Acharya Prashant explains that the word 'Guru' specifically refers to one who can dispel the inner darkness of the 'I-sense' or ego. He clarifies that while individuals who provide guidance on physical health, financial management, or marketing perform useful societal roles, they should be called 'teachers' or 'instructors' rather than 'Gurus'. A true Guru's sole focus is the liberation of the 'I' from its attachments to worldly objects and the body. Using the term 'Guru' for mundane experts diminishes the dignity of the word and reflects a lack of seriousness toward one's own spiritual potential.