The terms “self-employment” and “freelance work” are often used as synonyms. The article points to the differences in the meaning of these concepts, as well as to various ways of defining them. The author cites numerous definitions proposed by science, Polish and foreign subject literature, as well as given in acts of Polish and international law. Due to the evolution of modern forms of work, the phenomenon of “networking,” “hybrid employment” and other forms of self-employment have also been described, which have been gaining popularity in recent years, especially in the “digital economy” sector. The article presents the abundance of sources and views of researchers analyzing “self-employment” as an important element of the modern economy.