What is a Sidebar?
A Sidebar in WordPress is referred to a widget-ready area used to display information that is not a part of the main content. In most cases, it is a vertical column on the side.
Sidebars play an important role in designing the layout of a website to display content other than the main articles of a website. For example, a short list of recent articles, recent comments, a list of pages, or popular articles on a website can easily be displayed across the entire site.