The term preferred pronouns is used to mean the personal pronouns a person identifies with and would like to be referred to by. People usually state the subject and object pronoun (e.g., ‘she/her’) but may also include the possessive (e.g., ‘she/her/hers’).
Most people go by the masculine ‘he/him’, the feminine ‘she/her’, the gender-neutral singular ‘they/them’, or some combination of these. There are also neopronouns used to express nonbinary gender identity, such as ‘xe/xem’. These are less common than the singular ‘they’.
The practice of stating one’s preferred pronouns (e.g., in a professional context or on a social media profile) is meant to promote inclusion for transgender and gender-nonconforming people.