How to distinguish a data structure from an enumeration and what are their main differences?

Data structures (struct) and enumerations (enum) are different data types used for different purposes:

• Structure (struct) — a data type that combines multiple values (fields) of different types into a single entity. It is useful when you need to store related data together. For example, a "Point" structure might contain x and y coordinates.

• Enumeration (enum) — a data type that defines a set of named constants, usually associated with a limited number of options. Enumerations are convenient for representing states, options, or categories.

Example in Swift:

struct Point {
    var x: Double
    var y: Double
}

enum Direction {
    case north
    case south
    case east
    case west
}

Main difference: a structure stores data with different fields, while an enumeration is a choice among fixed options.