You typed some text to make your first comment, and it looked something like this:

Elder Millennial here. All I know about markdown is:

1. To make a hard copy of a thought or conversation. "Mark that down in your notes, so we don't forget."

2. A discount or sale. "Did you see the 30% markdown on three legged jeans?"

The way your comment actually displays is different though, isn’t it? The numbered items are indented and come one after the other without any space inbetween, and the text within each numbered item is properly aligned.

What you entered is just text, and text by itself is inherently meaningless. “Markdown” is the name of a particular standard way of formatting text so that programs can reliably interpret parts of that text as representing the writers desire for their text to be displayed a particular way. You can kind of think of it like a programming language. As another basic example, consider this text:

This is a paragraph.
This        is still    the same
       paragraph.

Here is the second one.





And here is the third                   one.

I’m going to paste this text right after this sentence; notice how the amount of space doesn’t matter, and how a new paragraph is denoted by at least two line breaks.

This is a paragraph. This is still the same paragraph.

Here is the second one.

And here is the third one.