Imagine you have a long blog post or an article on your website!
When search engines like Google, Bing, or Yahoo are analyzing the content on your webpage, they try to understand it so they can provide richer search results.
One way to help them is to provide on-page markup. With markups, you can annotate the raw text on your blog and provide more information on the structure and relations between them.
One of the famous markups which is supported by major search engines is Schema.org. Schema.org is the result of a collaboration between Google, Bing, Yandex, and Yahoo! to improve the web by creating a structured data markup.
Markup expert is a tool which helps you generate structured-data markup by analyzing the content of your webpage and suggests Schema.org markups that can be added to your website.