Type

Perl has a feature called "type coercion" which means that it can use the context of a variable's use to determine the type of the value contained inside.  It can freely convert values from string to number and back:

    "4" + "5" # 9
    4 . 5     # "45"

All of which means that in Perl you don't often have to think about other languages' notions of type.  Perl "does what you mean." (Most of the time.)