How is the Top News block different from the Recent News block?

Actually their isn't a difference at all, only the default settings are set to different values for each block. The blocks are actually eachothers clones so to speak.

The first block (top) shows news items in order of hits, meaning it's ordered from most to least hits. The second block (recent) displays news according to post date, Latest item on top.

This Q&A was found on XOOPS Web Application System : https://xoops.org/modules/smartfaq/faq.php?faqid=414