A Kar Sevak is someone who offers services for free (that is, a volunteer) to a religious cause. It originates from the Sanskrit

Sanskrit

Sanskrit , is a historical Indo-Aryan language and the primary liturgical language of Hinduism, Jainism and Buddhism.Buddhism: besides Pali, see Buddhist Hybrid Sanskrit Today, it is listed as one of the 22 scheduled languages of India and is an official language of the state of Uttarakhand...

 words kar (hand) and sevak (servant).

Although the term has recently been used ostensibly in the context of Hindutva

Hindutva

Hindutva is the term used to describe movements advocating Hindu nationalism. Members of the movement are called Hindutvavādis.In India, an umbrella organization called the Sangh Parivar champions the concept of Hindutva...

, a kar sewak may be working towards any theological denomination. After Operation Blue Star

Operation Blue Star

Operation Blue Star ) 3– 6 June 1984 was an Indian military operation, ordered by Indira Gandhi, then Prime Minister of India, to remove Sikh separatists from the Golden Temple in Amritsar...

, Sikh

Sikh

A Sikh is a follower of Sikhism. It primarily originated in the 15th century in the Punjab region of South Asia. The term "Sikh" has its origin in Sanskrit term शिष्य , meaning "disciple, student" or शिक्ष , meaning "instruction"...

 Kar Sevaks helped in rebuilding the Harmandir Sahib

Harmandir Sahib

The Harmandir Sahib also Darbar Sahib , also referred to as the Golden Temple, is a prominent Sikh gurdwara located in the city of Amritsar, Punjab . Construction of the gurdwara was begun by Guru Ram Das, the fourth Sikh Guru, and completed by his successor, Guru Arjan Dev...

, the holiest Sikh

Sikh

A Sikh is a follower of Sikhism. It primarily originated in the 15th century in the Punjab region of South Asia. The term "Sikh" has its origin in Sanskrit term शिष्य , meaning "disciple, student" or शिक्ष , meaning "instruction"...

 shrine. Subsequently, It has been adopted to refer to people who often pay visit to the controversial historic Hindu holy site Ram Janmabhoomi

Ram Janmabhoomi

Ram Janmabhoomi is the "Birthplace of Lord Rama."Lord Rama is a major God in Hindu theology and the Hindu religion where He is described as an Avatar of Lord Vishnu in Hinduism. The exact location of Lord Rama's birth as stated in holy Ramayan as being in the city of Ayoudhya in Uttar Pardesh...

 to perform building or prayer activities, the former site of Babri Mosque

Babri Mosque

The Babri Mosque , was a mosque in Ayodhya, a city in the Faizabad district of Uttar Pradesh, on Ramkot Hill . It was destroyed in 1992 when a political rally developed into a riot involving 150,000 people, despite a commitment to the Indian Supreme Court by the rally organisers that the mosque...

 in Ayodhya, Uttar Pradesh

Uttar Pradesh

Uttar Pradesh abbreviation U.P. , is a state located in the northern part of India. With a population of over 200 million people, it is India's most populous state, as well as the world's most populous sub-national entity...

.