The hand is a navigation tool to pan around your canvas. The default hotkey for this is the spacebar.

Either select your hand tool, or hold down your spacebar, then click and drag to move your canvas in any direction.

While the hand tool is active, pressing and holding Ctrl switches it to the Zoom tool.

If you have another tool selected, pressing and holding Spacebar and then Ctrl will also activate this. When you release, you will jump back to your previously-active tool.

While the hand tool is active, pressing and holding Alt switches it to the rotate tool.

If you have another tool selected, pressing and holding Spacebar and then Alt will also activate this.