If you maintain a research webpage, or usea teacher page for health products, then you'll want to check out the new widget code from Medline Plus (government sponsored medical website) to copy and paste on your page: http://www.nlm.nih.gov/medlineplus/linking.html
You ask, "What's a widget?"
I like to think a widget is a visual hyperlink with power. A widget provides a direct path from your webpage to some other page, or product (such as a database) while at the same time, ties a link to what you are looking for in the other location.
You have probably received widgets embedded into an email that will let you search (or shop) in a catalog for some necessity you were looking for-- perhaps flights downsouth to escape the winter snow?
Some EBook publishers are starting to release widgets for webpages that will lead the reader to their EBook. Contact your favorite database vendor and ask for a widget for your teaching page, library page, etc.