Markdown is a lightweight markup language that you can use to add formatting elements to plaintext text documents. Created by John Gruber in 2004, Markdown is now one of the world’s most popular markup languages.
Using Markdown is different than using a WYSIWYG editor. In an application like Microsoft Word, you click buttons to format words and phrases, and the changes are visible immediately. Markdown isn’t like that. When you create a Markdown-formatted file, you add Markdown syntax to the text to indicate which words and phrases should look different.
For more details read the guide for the MARKDOWN.
Shortcode is a small piece of code, indicated by brackets like
[this], that performs a dedicated function on your site. You can place it just about anywhere you’d like, and it will add a specific feature to your page, post, or other content. For example, you can use shortcodes to display galleries, videos, or even playlists.
For more details read the guide for the SHORTCODE.