Question: How Usenet groups are different from Yahoo or Google groups? How can i subscribe to any usenet groups? 

Answer: USENET are distributed "news groups" that use NNTP to distubute the messages to servers through out the internet.\n\nYahoo Groups is a comunnity of interest that got together using a web based message board.\n\nYou can read USENET using Google\nhttp://groups.google.com
This question from the Yahoo Q&A forum is categorized in the topic: Education & Reference