Karma yoga, also called karma-marga, is one of the several spiritual paths in Hinduism, one based on the "yoga of action". To a karma yogi, right work done well is a form of prayer. Of the paths to spiritual liberation in Hinduism, karma yoga is the path of unselfish action. It teaches that a spiritual seeker should act according to dharma, without being attached to the fruits or personal consequences. 

Karma yoga, states the Bhagavad Gita, purifies the mind. It leads one to consider dharma of work and the work according to one's dharma, doing god's work and in that sense becoming and being "like unto god Krishna" in every moment of one's life.  

Take a listen to the Karma Yoga, narrated beautifully by Grant Finley.