What are the smallest stars?what are the medium and the largest stars?

Read lots and read carefully:

http://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=smallest+stars&*

http://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=medium+stars&*

http://en.wikipedia.org/wiki/List_of_largest_stars