This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
You can think of portlets as mini application windows existing cohesively on a page.
One real life example of a portlet is iGoogle which allows you to customize your page with "widgets" These widgets are the portlets