Masculinity is a set of attributes, behaviors, and roles associated with men and boys. Masculinity can be theoretically understood as socially constructed, and there is also evidence that some behaviors considered masculine are influenced by both cultural factors and biological factors. To what extent masculinity is biologically or socially influenced is subject to debate. It is distinct from the definition of the biological male sex, as anyone can exhibit masculine traits. Standards of masculinity vary across different cultures and historical periods.

A man is an adult male human. Prior to adulthood, a male human is referred to as a boy.