Neopronouns
Neopronouns are any set of singular third-person pronouns that are not officially recognized in the language they are used in, typically created with the intent of being a gender neutral pronoun set. In English, and many other Indo-European languages, third-person pronouns can be gendered. In English, "she/her" is most often used by women, "he/him" most often by men, and "they/them" by non-binary people, though some people deviate from this convention.
Some people prefer using neopronouns as an alternative gender neutral pronoun set. This could be because they want to avoid singular "they" being confused with plural "they", because neopronouns express something about them or their gender (like xenogenders), or because they feel more comfortable using neopronouns over any of the standard pronoun options.