It's complicated, because it depends on the verb being strong, weak, regular, irregular or mixed. Just to give you an idea: https://www.thoughtco.com/examples-regular-and-irregular-verbs-4069886
"Drinks" - when it is a repeated action, e.g. he drinks whiskey (he likes whiskey, he likes to relax with a nice glass of whiskey). "Is drinking" - when one is describing a present action, such as when you see a person having a drink of whiskey in their hand, you say "he is drinking whiskey". Right now, on this very moment.
Of course, there are plenty other little differences, but this is the most basic distinction, hope this helps