All Sikh males should use the term Singh as part of their names. It activates a sense of brotherhood and courage. Historically, the Singhs are known for their braveness and chivalry. Sikh is considered a spiritual title, while Singh has social and political implications.
However, not only Sikhs use the name Singh. Many Hindus from North India use it as well, usually as a surname, and this name is also known in other Asian countries such as Sri Lanka, Nepal and Bangladesh.