When you pan a document in Inkscape, you just shift the visible area inside the window without changing the zoom. It’s basically the same as scrolling, except that scrolling assumes a single axis (e.g., up and down) whereas panning can be done in any direction. It is, right up there with zooming, one of the most common things you do when you work in a vector editor.
An Inkscape document window has the traditional scrollbars that you can use to scroll both horizontally and vertically to reach any point on the canvas. Scrollbars, however, are pretty clumsy, so I usually prefer other methods for panning and turn the scrollbars off (
) to free up some extra room for the artwork.
There are simple ways to pan using both the keyboard and the mouse. With the keyboard, press 
with the arrow keys to scroll in any of the four directions. This is more handy than it may sound, because if you press and hold along with an arrow key, the canvas movement accelerates. This means you can budge the canvas position a little by single strokes of and an arrow key, or swoosh it quickly aside if you press and hold. The speed of and arrow key scrolling (i.e., the distance for a single keystroke) can be set in the Scrolling tab of the Inkscape Preferences dialog.
With the mouse, the easiest way to pan the canvas is by dragging it around with the middle button. Again, this works in any tool or mode. There’s no dedicated “hand” tool for panning in Inkscape. You can also scroll vertically with the scroll wheel on your mouse and horizontally by 
-wheel.
Inkscape tries to make panning automatic whenever possible. For example, when you drag selected objects with the Selector tool and push them against the edge of the screen, the canvas will automatically scroll under you. Also, when you select a new object or path node with the 
key, Inkscape scrolls to make this object or node visible.
AI
Canvas panning is one of the areas where Inkscape’s user interface is noticeably different from that of its biggest competitor, Adobe Illustrator. Many Illustrator users are used to panning by pressing the spacebar and dragging with the left mouse button. In Inkscape, however, pressing the spacebar in any tool temporarily switches you to the Selector tool (hitting the spacebar again switches back to the tool you were in before). Specially for Illustrator refugees, Inkscape offers a compatibility option: With the spacebar pressed, the left mouse button will drag the canvas. Enable this option in the Scrolling tab of the Inkscape Preferences dialog.