Gurmukh – Manmukh – Sunmukh – Vaymukh
Gurmukh literally means Guru's mouth / voice/
The Gurmukh lives for truth and righteousness. Having bathed in the pool of truth the soul of the gurmukh is purified. Truth pervades his speech, Truth bedecks his vision, Truth fills his actions, too. To a gurmukh alone is Truth revealed, for he is rid of doubt, delusion and pride. (Read about a Gurmukh on page 1058 of the Siri Guru Granth.)
In the Guru Granth Sahib the word gurmukh is used in its literal sense of the face of the Guru. "Beholding the Guru's countenance, one attains the highest bliss”.
A Gurmukh is one who follows the way of life prescribed by the Guru and acts on his precepts. In this sense, he has his face turned towards the Guru.
Manmukh which means a person who follows his own uncontrolled mind or wild desires.
The Manmukh is the ego-centered one, who has turned his face away from the Guru.
Sunmukh & Vaymukh:
Bẖagaṯ janā ka▫o sanmukẖ hovai so har rās la▫e vaimukẖ bẖas pāhu.
"That humble devotee who turns his face towards the Guru and becomes sunmukh, receives the Lord's wealth; the faithless vaymukh, who turns his face away from the Guru, gathers only ashes."
Vaymukh: One who has turned his or her back on the Guru and is deprived of spirituality.