I got that. The bottommost line is the status bar for the lack of a better term and the line above it is the status line (confusing, I know). Ruler is in the right part of the status bar. Another thing there is input prompt that displays g when you're in the middle of typing gg.
The whole thing can't be hidden because it also displays messages. The only possibility is to make it appear automatically for command-line mode and when there is a message to show.