Hari is one among the numerous names of Hindu God Vishnu. The name is mentioned in the Vishnu Sahasranama.
Adi Shankaracharya defines Hari as one who destroys Vasanas, maya, ignorance and samsara.
Swami Chinmayananda defines Hari as one who loots all the vasanas or ignorance and frees a devotee and prepares him to realize the Supreme Truth.
For Example take the prayer Hari Om…
The aim of a devotee is to reach Om but is constantly weaned away by ignorance and desires. Hari is the one who crushes all the ignorance and desires and puts the devotee in the path of self realization.
Hari is the power that helps to quieten the mind and fill it with Brahman consciousness.