Pi 3 compared to Pi 2
1. More processor speed. The CPU on the Pi 3 is one and a half times faster at 1.2 GHz. Your Pi board performs better.
2. On-board connectivity. The Pi 3 features 802.11 b/g/n Wireless LAN and Bluetooth Classic & Low Energy (BLE). You can get connected much quicker without the need for any external device.
3. 2.5 A power supply. With more processor speed and on-board connectivity, you’ll need more power. Power supplies for previous Pi boards will not be sufficient. You will need the Official Raspberry Pi Power Supply
4. New components. The Pi 3 features a chip antenna where status LEDs were located previously. The status LEDs are still on the board, right next to the microSD card slot.