Who discover set?

Answer 1

Although the concept of sets is ancient, the modern theory of sets was developed by Georg Cantor and Richard Dedekind in the late 19th Century.

Answer 2

It is difficult to say whether the word "discovered" is appropriate, but the person responsible for introducing the concept of a set was George Cantor near the end of the 19th century. Early on, the vague definition of set and element was criticized by the mathematics community, but ironically, set theory has become the foundation of modern mathematics. Even today, the vagueness of sets generates debate about their true interpretation.