A WordPress Widget is a small block that performs a specific function. You can add widgets in sidebars also known as widget-ready areas on your web page. WordPress widgets were created to provide a simple and easy-to-use way of giving design and structure control of the WordPress theme to the user.
Widgets can be added, removed, and rearranged in the WordPress Administration area in Appearance > Widgets.
Default widgets that come with WordPress are display of categories, tag clouds, search forms, etc. Plugins will often add their own widgets to enhance their functionality.
