What does the severity level of errors depend on?

In programming, the term "frozen" usually means that an object or data structure has become immutable after a certain point. For example, in Swift, there is a Frozen protocol (in some libraries) or the concept of a "frozen" state, where an object cannot be changed — this helps prevent errors related to data modification.

In iOS development, immutable objects are often used (for example, let instead of var), which can be considered a "frozen" state. This increases code safety and makes it easier to understand.

Example in Swift:

struct User {
    let name: String
    let age: Int
}

let user = User(name: "Ivan", age: 30)
// user.name = "Petr" // Error: cannot modify, properties are declared with let

Here, the structure and its properties are "frozen" — they cannot be changed after creation.