The zoom controls in the status bar decide how big your document looks on screen. Don't worry: the zoom doesn't change anything in what you print.

The controls
Fit width	Makes the page as wide as the work area. New documents open this way.
Fit page	Makes a whole page fit in the work area.
Zoom out, Zoom in	Make the document smaller or bigger. Hold Ctrl while clicking to change the zoom by one percent at a time.
The zoom	Shows the zoom as a percentage. Click it to go back to 100%.

The zoom goes from 25% to 800%. Zoom in and Zoom out take small steps when the document is small and bigger ones when it's large. You can also zoom by holding Ctrl and turning the mouse wheel.

With Fit width or Fit page, the zoom follows the size of the window. Zoom in or out and you leave the fit: the zoom then stays where you put it. Each document remembers its own zoom and view, and saves them with the file.

The zoom has keyboard shortcuts too: see Keyboard shortcuts.