A permanent contract is one wherein no specific period is stipulated for the marriage. A woman who is married in such a contract is known as a d¡’imah (permanent wife).
A temporary contract is one wherein a specific period is stipulated for the marriage, such as forming a contract with a woman for a period of one hour, one day, one month, one year or more. The obligatory precaution is that the period of such a marriage should not exceed the lifespan of the husband and wife, or one of them. A woman who is married in such a contract is known as a mut‘ah (temporary wife).