Sate your curiosity and read the next 21 words following your quote.
> , “subtyping” might call to mind classes and inheritance hierarchies. However, subtyping is a far more basic and general notion than that.
> , “subtyping” might call to mind classes and inheritance hierarchies. However, subtyping is a far more basic and general notion than that.
Yes, there are other forms of subtyping, but saying that many languages don't have subtyping just because they don't have these other forms of subtyping is either cluelessness or satire.