What are your understandings of markdown meaning? Markdown might have been used without your knowledge. In Skype, Reddit, and Facebook chat, you can format your messages with a variety of Markdown styles.
Here's a simple illustration: with Markdown; you just wrap words in * to make them bold (asterisks) (asterisks). At the end of the day, "bold word" will still appear to be a bold word.
To sum up, Markdown is an excellent plain text authoring technique for the web.