The term marriage refers to the interpersonal union established in various parts of the world to form a familial bond that is recognized legally, religiously, or socially and which grants the participating partners mutual conjugal rights and responsibilities. A first marriage occurs for couples who have never been married before. A second marriage refers to the act of remarrying after an initial first marriage ends due to death or divorce. Current statistics indicate that approximately 50% of first marriages and 60% of second marriages end in divorce, prompting researchers to investigate these trends further. The purpose of this entry is to provide an overview of research on heterosexual first and second marriages, the intricacies of each relationship type, and the impact of counseling for couples ...