The z-order determines the order in which objects are drawn on the canvas. Those object with high z-order are drawn last and therefor drawn on top of objects with lower z-order. The order is determined by the order that the objects are listed in the SVG file.

The yellow star has the highest z-order on the left but the lowest on the right.

Inkscape has a number of commands to change z-order. The commands are available from the Menu and via Keyboard Shortcuts. They are also available in the Controlli Strumento when the Strumento Selettore is active.

The Editor XML dialog can also be used to change z-order.