You can view all of your available widgets in the Widgets area of your Dashboard (under Appearance).
Below is a list of common WordPress widgets and their descriptions.
ARCHIVES – displays archive links for each month that has posts
- Title — description that appears over the list of archive links
- Show post counts — if checked, this box causes a count of the number of posts for each archive period
- Display as a drop down — if checked, this box causes the archives to be displayed in a drop-down box
CALENDAR – displays a calendar of the current month. Dates appear links if there are posts for that day
- Title — description that appears over the calendar
CATEGORIES – displays a list of post categories as links to those posts
- Title — description that appears over the list of categories.
- Show as dropdown — if checked, this box causes the categories to be displayed in a dropdown box
- Show post counts — if checked, this box causes the count of the number of posts to display with each category
- Show hierarchy — if checked, shows parent/child relationships in an indented manner
LINKS – displays list of links (blogroll) separated by category
META – displays links to meta functions such as Register, Site Admin, Login/out, Entries RSS, Comments RSS, and WordPress.org
- Title — description that appears over the list of meta links. You can rename this to Login, Admin, Dashboard, etc.
PAGES – displays a link to each Page
- Title — description that appears over the list of pages
- Sort by — select the order to sort the list of pages. Choose Page Title, Page Order, or Page ID from pulldown box
- Exclude (Page IDs, separated by commas) — enter the Page ID(s) to exclude, separating each Page ID with a comma
RECENT COMMENTS – displays a list of the blog’s most recent approved comments
- Title — description that appears over the list of recent comments
- Number of comments to show — (at most 15); enter the number of comments to be displayed
RECENT POSTS – displays list of the blog’s most recent posts
Title — description that appears over the list of recent posts
Number of posts to show — (at most 15); enter the number of posts to display
RSS – displays an RSS Feed. Multiple instances of this widget can be added to the Current Widgets list. Using RSS Widgets lists several feeds to use with this widget
- Enter the RSS feed URL here — enter a complete feed URL, e.g. http://wordpress.org/development/feed/
- Give the feed a title (optional) — enter a description that appears over the list of feed items
- How many items would you like to display — enter the number of items from the feed you want displayed
- Display item content?— check this to display the content of the feed
- Display item author if available — check this to display the author of this particular item content
- Display item date — check this to display the date the item was published
SEARCH – displays a Search box to enter text to search your blog. A submit button is also provided
TAG CLOUD – displays list of the blog’s top 45 used tags in a tag cloud
- Title — description that appears over the tag cloud
- Taxonomy — select the desired registered taxonomy (e.g. Post Tag, Category)
TEXT – used to enter HTML, Javascript, or just plain text. Multiple instances of this widget can be added to the Current Widgets list. Using Text Widgets details a number of possible uses for text widgets
- Title area — a description of the text widget
- Text area — use this area to enter text, valid HTML, or even valid Javascript
Source: WordPress Widgets