‘Om Namo Bhagavate Vaasudevaya’ is a mantra.
A mantra is the result of a vision of a seer / a concrete manifestation of the deity through the world of language, which is made to manifest in the mantra.
When we chant a mantra correctly and systematically with proper intonation, it set up a vibration in the nervous system / a harmony is established in the whole world.
‘Om Namo Bhagavate Vasudevaya’ is a mantra of Bhagavan Sri Krishna. It means literally: “Prostration to Bhagavan Vasudeva.”
It is an external symbol of the internal union.
Thank you my friends.