Reference: Adding Widgets
WordPress offers a variety of default widgets such as Search, Recent Posts, Links, Calendar, etc. These widgets can be added to your Organic Themes sidebar and other “widgetized” sections of your theme. Various plugins can be installed within WordPress to provide additional widgets.
Navigate to the Appearance > Widgets section within the WordPress administration. Drag and drop your desired widgets in to the sidebar or widgetized section of your choosing. After dragging and dropping the widget, configure and save the widget settings.