Widgets are placeholders, they display an information arrangement changeable by the user. Widgets make it easy to customize the content of your blog sidebar without having to change any code.
Your theme will come with predefined default items in your sidebar. A widgetized theme allows you to replace your theme’s sidebar with a dynamic one while still falling back on the old sidebar in case you remove all the widgets. You can add, arrange, customize, and remove widget content from the sidebars of your blog through the Appearance menu in your wp-admin.
IMPORTANT! With most themes when you start to add widgets to your sidebar all other sidebar items will be removed and your entire sidebar will be replaced with widgets.
If your theme is not equipped to use widgets you can add a few lines of code to enable this function. (Widgetizing Themes WordPress Codex)
A look at the wp-admin widgets page:
- AVAILABLE WIDGETS: Drag widgets from here to a sidebar on the right to activate them. Drag widgets back here to deactivate them and delete their settings
- INACTIVE WIDGETS: Drag widgets here to remove them from the sidebar but keep their settings should you wish to restore them at a later date.
- SIDEBARS: In the right column you will see one Sidebar or multiple sidebars depending on your theme. Drag items to and from this area to add or remove them from appearing on your site.
After adding a new plugin to your site, have a look at widgets to check if the new plugin came with an associated widget to further customize your sidebars.
This instructional video is using an old version of WordPress but it covers the basic steps to add and move widgets in your sidebar.
