Is there any difference in the GPIO layout between Raspberry Pi 2 B and 3 B? If yes, please provide the differences.
It basically depends on what aspect you are looking at.
The pins of all with 40pin headers (B+, Pi2, Pi3) are identical.
The functions which are allocated to the pins differ slightly. The Pi3 has a different UART assigned to the serial pins, and there is some difference in the 2nd I²C (which are normally reserved).
If you run
gpio readall this will show current state.
gpio SHOULD be installed, but was missing from some releases. It can be installed as part of
wiringpi if missing.