The main and primary reason why someone would want to use a graphics tablet is to aid their input to a computer. A graphics tablet is a device that allows the user to use a stylus or pen to make strokes and marks like a normal pencil on paper but the marks appear on the computer screen within the chosen application.
When combined with an application such as Microsoft Paint, GIMP or Adobe Photoshop the device allows the user to draw, paint and perform creative functions with the computer as if they were drawing or painting using traditional artists media. Some artists use the mouse as an input device for drawing on the computer and creating digital artwork, but a graphics tablet or digitizing pad device is much better suited to this task.
The pen that is supplied with the graphics tablet is a wireless or an untethered device that allows the user to place the point anywhere on the active area of the tablet and the computer will place the mouse cursor in the corresponding place on the screen. When the pen is raised from the active area on the tablet and moved to a new location, the mouse cursor follows the movement and therefore provides 1-to-1 mapping between the device and the screen.
This allows the user to experience no barriers between using the technology and their creativity. The stylus acts as their paintbrush or pencil and the computer software provides the brushes, colors, designs and creative elements they need. The stylus pen is also sensitive to 1024 levels of force, so the lighter you touch the tablet, the lighter the stroke will appear on the screen. If you think of watercolor painting, this would provide different levels of transparency and the ability to perform washes of color.
A graphics tablet can also be used as a text input tool. Software is available that can track, recognize and convert any written text that is entered via the tablet and change it to be normal words that can be edited in any word processing application. The tablet also allows you to annotate documents or files with written notes or highlights and also mark areas for reworking or importance.
What ever you can do with a mouse, you can do with a graphics tablet too. As it provides 1-to-1 tracking between the active area and the screen, you can use it to click on menu items, double click icons or any other mouse related gesture or function.