Can you explain what the term 'optional' means in programming?

In programming, the term "optional" refers to a data type that can contain either a value of a specific type or no value at all (nil, null). This allows explicitly handling the possibility of missing data, avoiding errors related to null.

In Swift, for example, an optional is declared with a question mark:

var name: String? = "Ivan"
name = nil // now the variable does not contain a value

To access the value of an optional, you need to "unwrap" it, for example, through conditional binding:

if let actualName = name {
    print("Name: \(actualName)")
} else {
    print("Name is missing")
}

Optionals help safely work with variables that may be empty.