What information does a variable of type value contain?

A variable of type value in iOS (for example, structures or primitive types) directly contains the data, not a reference to it. This means that when assigning or passing such a variable, a copy of the values is created. For example, a CGPoint structure contains x and y coordinates, and a variable of this type stores exactly these values.

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

var p1 = Point(x: 10, y: 20)
var p2 = p1 // a copy of the values of x and y is created
p2.x = 30
// p1.x remains 10, as it is a copy

Thus, a variable of type value stores data directly, not a reference to an object.