Wiktionary
n. Any job in which sex or eroticism is involved, especially prostitution or pornography.
Wikipedia
Sex work is "the exchange of sexual services, performances, or products for material compensation. It includes activities of direct physical contact between buyers and sellers ... as well as indirect sexual stimulation" The term emphasizes the labor and economic implications of this type of work. Furthermore, some prefer the use of the term because it seemingly grants more agency to the sellers of these services.
Because of the agency associated with the term, "sex work" generally refers to voluntary sexual transactions; thus the term does not refer to human trafficking and other coerced or nonconsensual sexual transactions. Due to the legal status of some forms of sex work and the stigma associated with sex work, the population is difficult to access; thus there has been relatively little academic research done on the topic. Furthermore, the vast majority of academic literature on sex work focuses on prostitution, and to a lesser extent, exotic dancing; there is little research on other forms of sex work. These findings cannot necessarily be generalized to other forms of sex work. Nonetheless, there is a long documented history of sex work and its personal and economic nature.