The Property inspector lets you examine and edit the most common properties for the currently selected page element, such as text or an inserted object. The contents of the Property inspector vary depending on the element selected. For example, if you select an image on your page, the Property inspector changes to show properties for the image (such as the file path to the image, the width and height of the image, the border around the image, if any, and so on).
The Property inspector is at the lower edge of the workspace by default, but you can dock it at the upper edge of the workspace, or make it a floating panel in the workspace.