In a Gurdwara, no special place or seat may be reserved or set aside for any dignitary, as all are considered equals. The service consists of singing of the liturgy, as well as the exposition of Sikh history, tradition, and theology. In traditional Indian society, people of high and low caste were rigidly segregated. To combat this social problem, the Sikh community kitchen, or "langar", requires everyone to sit side by side and eat together, thereby teaching the concept of equality by shattering all barriers of caste and class. Every major city in the United States and Canada has Sikh gurdwaras and they are open to all Sikh people go to Gurdwara to worship God.