Look at the default theme. It uses both.
Yes, the default theme uses both, yet you need to be WP smart to figure out what they are for.
The archive.php is in the template hierarchy as explained in the Template Hierarchy article in the Doc section.
The archives.php is a custom template file which isn’t used unless you select it under the page template option when you create a new Page. The fact that it just happens to be called archives.php is of no consequence. You could rename the file to diddlysquat.php and it wouldn’t change anything. However the absence of archive.php would default back to the index.php when an archive is called on by the server.
now i know what the difference between the two file. tnx jberghem
