What is the difference between the access modifiers 'fileprivate' and 'private' in Swift?

In Swift, access modifiers private and fileprivate restrict code visibility but differ in their scope:

• private limits access to the same declaration (e.g., class, struct, or extension). Even within the same file, outside this declaration, access is denied.

• fileprivate allows access to the entire element within the same file. That is, all types and functions in one file can see fileprivate elements.

Example:

class MyClass {
    private var privateValue = 1
    fileprivate var fileprivateValue = 2
}

extension MyClass {
    func test() {
        print(privateValue)       // Accessible, as in the same declaration
        print(fileprivateValue)   // Accessible
    }
}

func outside() {
    let obj = MyClass()
    // print(obj.privateValue)    // Error: private outside the class
    print(obj.fileprivateValue)  // Accessible, as in the same file
}

Thus, private is the most restrictive level, limited to the declaration, while fileprivate extends accessibility to the entire file.