In C, enumerations (or enums) are user-defined data types. Enumerations allow integral constants to be named, which makes a program easier to read and maintain. For example, the days of the week can be defined as an enumeration and can be used anywhere in the program.
Enumeration or Enum in C is a special kind of data type defined by the user. It consists of constant integrals or integers that are given names by a user. The use of enum in C to name the integer values makes the entire program easy to learn, understand, and maintain by the same or even different programmer.