The Raspberry Pi 2 Model B is the second-generation Raspberry Pi. It replaced the original Raspberry Pi 1 Model B+ in February 2015.
Compared to the Raspberry Pi 1 it has:
A 900MHz quad-core ARM Cortex-A7 CPU 1GB RAM
Like the (Pi 1) Model B+, it also has:
4 USB ports 40 GPIO pins Full HDMI port Ethernet port Combined 3.5mm audio jack and composite video Camera interface (CSI) Display interface (DSI) Micro SD card slot VideoCore IV 3D graphics core
