The launch has been one of the most highly anticipated debuts for a new electronic gadget in recent years. Apple Chief Executive Officer Steven Jobs called the slim, mulitimedia device "magical and revolutionary."
The tablet -- as flat digital readers are called -- is 9.7 inches tall, a half inch thick and weighs 1.5 pounds, The New York Times reported.
The iPad is based on a touch-screen, similar to the iPhone and iPod Touch. Besides displaying reading material in color, the device allows users to browse the Web, handle e-mail, watch videos, view photos and listen to music.
Instead of using space to include a keyboard, a virtual keyboard appears on the touch-screen, allowing the user to send e-mail. In a user-friendly feature, contents displayed on the screen flip automatically to an upright position if the user turns the iPad sideways or upside down.
The more sophisticated models will sell for $829 and include 64 gigabytes of memory and 3G cellphone capabilities. The base model with WiFi and 16 gigabytes of memory will sell for $499, Jobs said.
Accessories include a charging dock, a physical keyboard dock and a case that holds the iPad upright.
At its unveiling, Jobs called the iPad "so much more intimate than a laptop and so much more capable of a smartphone with this gorgeous, large display."