Shiva is majorly seen in five of His aspects – Aghora, Ishana, Tat purusha, Vamadeva (Varna Deva) and Rudra (or Saddyojat). Panchavaktra or Panchamukhi is the combination of all these five forms and is commonly depicted as five-headed.
Aghora is the destructive aspect of Shiva. He is often depicted as the Keeper of burial and cremation grounds and is associated with death. He is said to devour life and make way for new creation or regeneration. He faces South on a Panchamukha Sivalingam.
Ishana is omnipresent and omnipotent. He is depicted as an all-pervading and eternal Shiva. He is cause of creation. He faces the north-east on a Panchamukha Sivalingam.
Tat purusha is the ego aspect of Shiva. Associated with meditation, enlightenment this form is often associated with sages, ascetics and celibacy. He faces east on a Panchamukha Sivalingam.
Vamadeva (Varna Deva) is the female aspect of Shiva. He is graceful and is associated with water. He faces north on a Panchamukha Sivalingam. He is a healer and bestower of health both mental and physical.
Rudra (Sadyojata) is the creative and destructive power of Shiva. He is associated with wrath and anger. He faces west on a Panchamukha Sivalingam.
Panchavaktra or Panchamukhi is the combination of all the five forms. Meditating on Panchamukhi (Panchavaktra) Shiva will bestow the aspirant with good mental health, the ability to see things clearly, protect one from all diseases, purify the mind and body, destroy ignorance and give control over sexual instincts.
The mantra for Panchamukhi Shiva is Shiva Gayatri.
Om Pancahvaktraye Vidmahe
Tanno Rudra Prachodayat