why under the keypad got one wierd pad? Trackpad?

I tried this phone at a Nokia stall ( dunno what to call it, it's not a shop )

I felt really baffled when I press the middle button and it went into the clock application.
Not used to this method since using all other Nokia phones, pressing middle button/menu button = menu. On this one need to use touch screen. But I find it quite nice considering it is an E-series. The feel of this phone is better than most other phones