‘Guru’ in Sanskrit literally means the one that ‘dispels darkness’ or, the one who ‘removes ignorance’.
Guru simply means one who brings more joy, more alertness, and more awareness into your life. A Guru helps you to dive deep into your own self and attain your goal.
A Guru is not just the one who teaches you some techniques or shows you a path. An acharya (or a teacher) gives knowledge; a Guru gives awareness and makes you alive. Acharya gives information; Guru gives awakened intelligence.