"I know about tablets like the iPad. So what is a graphics tablet?" you ask me. A graphics tablet is a nifty piece of technology that, with the use of a pen stylus instead of a mouse, measures pressure changes along with clicks. The basic set-up of a tablet is a flat, rectangular space the same size ratio of a standard computer monitor that is wired to detect pressure, taps, motion, and button clicks from a matching stylus. The location, motion, etc. of the stylus tip is translated to the cursor on-screen. In many ways it is like a mouse, in that it is used to interact with items on your computer. But the biggest difference is in its pressure sensitivity and particular method of moving the cursor.
The pressure sensitivity is the delicious custard at the center of graphics tablet technology. Mice and touchpads do not measure pressure - they are only designed to take input from button clicks. Professional-level image editors that use digital brushes such as Adobe Photoshop, PaintShop Pro, Corel Painter, and Gimp can be set up to detect pressure input from the tablet, and then map it to specific variables of the brush. The two most common variables are opacity and size - that is, when you press hard, you will get a bigger or more opaque stroke, and when you press light, you will get a smaller or more transparent stroke. So, what is the implication?
You will intuitively create strokes that emulate pens, paintbrushes, and pencils, because the stylus is acting like a pen or paintbrush. In my experience, the tablet feels and behaves on-screen most like a fountain pen, especially in the techniques I use for Dok Klaus Computer Care. Some tablets even come with special spring nibs for the stylus that take the paintbrush feel even further.
As for cursor motion, unlike a mouse, in which you are pushing and pulling the cursor on your screen with no way of using the real location of your mouse, the tablet surface is, by default, mapped to your screen. If you place your stylus tip anywhere on the tablet, your cursor will immediately jump to that location. This quirk is perhaps the only major hurdle to get over when using a tablet; Once you've gotten used to how the cursor moves, graphics tablets are incredibly intuitive and a delight to use.
The most popular and industry-used graphics tablets are manufactured by Wacom. They have three main lines of tablet, which go from hobby to professional level: the Bamboo, the Intuos, and the Cintiq. I recommend the Bamboo if you are purchasing one for a child or teen, if you're on a budget, or you are only a hobbyist. It works decently well and starts as low as $99. I personally use a medium-sized (8x10 active area) Intuos tablet, which, being at a professional level, has a higher pressure sensitivity than the Bamboo and is available in larger sizes. The average Intuos is about $300. The Cintiq is a special level of amazing: it is not only a graphics tablet with full functionality, it is also a spacious LCD display! It is the highest level offered by Wacom and is commonly used in bigger companies and is especially useful for TV, movie, or video game graphics. Because of display capacity, you will be drawing on its screen, breaking down the barriers between artist and work even further. The Cintiq also comes in touchscreen varieties. (You can't see, but I am swooning as I write this. If I had a choice between true love or a Cintiq 24HD Touch, I would probably choose the Cintiq.) However, quality comes with a price tag - in this case a shiny $1,000 price tag at the cheapest, or $3,700 if you're feeling fancy!
If you have your sights set on professional graphics and art, or you would like to take your illustration hobby to the next level, I cannot stress enough how a graphics tablet will change your life. Even if what you do does not involve mark-making or illustration, the nature of the tablet's cursor motion streamlines navigation around your computer screen. It even makes the creation of vector graphics more efficient! A graphics tablet breaks down the barriers between digital artist and artwork, bringing the intuition and freedom needed to work well and catalyze your creative potential.