Common widgets are ‘Recent Posts’, ’Recent Comments’, ‘Categories’ etc. They can be renamed. RSS Feed shows up to date activity on the site. ‘Search’ will provide a search bar on the site. ‘Tag Cloud’ will provide a selection of relevant tags. There are also social networking widgets available as links to Facebook, Twitter etc. ‘Text’ allows you to write text or HTML easily within having to make amendments in the back end of the site eg you could write a limited edition offer in the text widget rather than creating a page/post for the offer. Some widgets are specific to individual themes therefore will not appear on other themes.