Question description

In Markdown, h1 through h6 are called "headings," not "headers." Each heading level represents a different level of importance, with h1 being the highest level and h6 being the lowest.

These should read Headings.
#Why does it read Header? A header is different.

In Markdown, a "header" typically refers to the metadata section at the top of a Markdown document, which is often used to store information about the document. This metadata section is also known as "front matter."