You can detach the keyboard of your device and use the screen as a tablet. Detaching the keyboard makes the device lighter and gives you the possibility to switch easily between laptop-mode and tablet-mode.
IPS (In-Plane Switching) is a technology used for LCDs. It was designed to overcome the main limitations of normal TFTs TN-matrices: relatively slow response times, small viewing angles and low quality color reproduction.
Thunderbolt is a connection that allows you to attach external peripherals to a computer, and can carry both data and display signals. Using a single port you can connect up to six devices through a hub or daisy chain configuration.