Bigamy is the act of marrying a second spouse while still legally married to the first spouse. According to the law, a person commits bigamy if he enters into another marriage contract during the lifetime of his existing spouse.
This is prohibited under the Indian Penal Code and various personal laws governing marriage, as it violates the legal principle of monogamy, which requires a person to have only one spouse at a time.
Therefore, a person commits bigamy if he marries again when his first wife is alive, without legally dissolving the first marriage through divorce or annulment.
Conclusion:
Bigamy occurs when a person takes another marriage while still being legally married to the first spouse, making such a second marriage illegal and punishable by law.