The Touchscreen of your device can be even more intuative than a computer mouse by using certain types of touch gesture. Below are some exaples of touch gestures.

• To select or desactivate an item, touch it once. e.g. to launch an application. 
• To move an item to a new location, tap and hold the item then then drag it to the desired location before letting go. 
• To scroll the screen, do a quick motion with your finger in the desired direction. For instance, swipe from bottom to top to scroll to the bottom.
• To zoom, double tap quickly the screen. Repeat the operation to zoom out. It doesn't work in every applications.  
• To zoom more precisely, splay two fingers on your screen to zoom in. or pinch them together to zoom out. It doesn't work in every application.