"Full touchscreen" means that the entire surface of the device's display is touch-sensitive, allowing you to interact with it by directly touching the screen with your fingers.
Design: This will be a sleek device with full touchscreen display with no dedicated buttons on the front side. (gogi.in)
This is especially true for those of us who have big fingers and struggle with the small keys on full touchscreen devices. (bgr.com)
This new full touchscreen device will be powered by a 1.2 GHz CPU and feature the highest resolution display to ever ship on a BlackBerry — 800 x 480 pixels. (bgr.com)