What's the difference between comma separated joins and join on syntax in MySQL?

What would the difference between these two queries be? They yield the same results.

SELECT * 
FROM Person 
JOIN Worker 
  ON Person.id = Worker.id;

and

SELECT * 
FROM Person, 
     Worker 
WHERE Person.id = Worker.id;

There is no difference at all.

https://stackoverflow.com/questions/20138355/whats-the-difference-between-comma-separated-joins-and-join-on-syntax-in-mysql