type alias vs value class

scala> type Location = String
defined type alias Location

scala> val loc: Location = "Washington"
loc: Location = Washington

//  ----

scala> case class Location(location: String) extends AnyVal
defined class Location

scala> val loc: Location = "Washington"
<console>:9: error: type mismatch;
 found   : String("Washington")
 required: Location
       val loc: Location = "Washington"
                           ^

scala> val loc: Location = Location("Washington")
loc: Location = Location(Washington)