Can you explain what ARC modifiers are in memory management?

ARC (Automatic Reference Counting) is a memory management mechanism in iOS and macOS that automatically tracks the number of references to objects and frees memory when an object is no longer in use.

Each object has a reference count. When a new reference to an object is created, the count increases; when a reference is no longer used, the count decreases. When the count reaches zero, the object is automatically removed from memory.

Example:

class Person {
    var name: String
    init(name: String) {
        self.name = name
    }
}

var person1: Person? = Person(name: "Ivan") // reference count = 1
var person2 = person1 // reference count = 2
person1 = nil // reference count = 1
person2 = nil // reference count = 0, object is deleted

ARC helps avoid memory leaks without the need to manually call memory release, as in traditional memory management. However, it is important to avoid retain cycles, which can prevent objects from being released.