typealias Number = NSNumber
You can also use a type alias to give a type another name to make it easier to remember, or make your code more elegant.
typealias for Tuples
typealias PersonTuple = (name: String, age: Int, address: String)
And this can be used as:
func getPerson(for name: String) -> PersonTuple {
//fetch from db, etc
return ("name", 45, "address")
}