👉 A functional is a mathematical object that has properties such as associativity, identity, and invertibility. These properties are essential in algebraic structures, such as groups, rings, and fields. In functional analysis, a functional is a type of linear operator on a vector space or Hilbert space. It can be thought of as a "function" that takes functions from one space to another and returns a function from the other space to itself. This allows for the study of properties like linearity and
