When I want to impress a Mathematica novice I show him how we can use spaces to denote multiplication (telling him also to be careful not to forget the space as in xy:-)!).
As far as I know this feature (or the feature for the exponent that suppresses the ^) does not exist in other CAS or programming languages (I am not sure about Maple) at least without importing packages.
So, what gives this ability of Mathematica? What is different in the implementation of multiplication? It has to do with Front End?
[]for function calls. That is WHAT allows a parser to be constructed that can unambiguously interpret the juxtaposition of expressions as multiplication. (That is the point of the duplicate.) The "power" is in the syntax. Previous designers of programming languages weren't bold enough to break with standard mathematical notation tradition (my opinion). – Michael E2 Apr 14 '18 at 01:19