Hi,Both displays use exactly the same controller and are connected exactly the same way.
this might be a noob qn, but I'm a newbie to arduino so pardon me.
So the qn is this: Are 16x4 LCD displays connected to the arduino the same way as 16x2 LCD displays?
Are there any other difference between the 2 other than coding?
As you surmised the only difference is in the coding. If you are using the LiquidCrystal library you do this with the lcd.begin(16, 2); or lcd.begin(16, 4); instruction. This instruction should set up the library to deal with each display correctly. Unfortunately the library does not correctly deal with the 16x4 displays so you may want to look into an alternative library if you are using one of these. The 20x4 works correctly.
If you want all the gory details then follow the LCD Addressing link at http://web.alfredstate.edu/weimandn.