When are module scripts (<script type="module">) fetched and evaluated?

Question

When exactly are module scripts (<script type="module">) fetched and evaluated?

Answer 1

According to the Living Standard for HTML (October 22, 2017.):

For module scripts,

if the async attribute is present,

then the module script and all its dependencies will be fetched in parallel to parsing, and the module script will be evaluated as soon as it is available (potentially before parsing completes).

Otherwise,

the module script and its dependencies will be fetched in parallel to parsing and evaluated when the page has finished parsing. (The defer attribute has no effect on module scripts.)