In History what does rank lower mean?

[Danette.Adams]

When reviewing history, I see the category 'rank' what did the user do or what action took place on the story?

[Bryce Lord]

Hi @Danette.Adams ,

Rank is used to arrange issues according to their relative importance or urgency. This is done by dragging and dropping the issue above or below another issue from either the backlog, timeline or board view. Issues moved to the top of the list have a higher rank (and so have higher importance or urgency) than issues moved to the bottom of the list.

Here's a great article on how to rank issues: Rank an issue 

Hope this helps!