Raspberry Pi is a ARM based single board computer (SBC). Small credit card size makes it ideal for many use full application. This ARM based SBC runs many Linux based OS. Raspberry pi is developed and made in UK. Raspberry pi Model B comes with 512MB RAM, 2 USB Host, one RJ45 socket for LAN and micro USB connector for power. Pi board also has some GPIO for connectivity and supports IIC, SPI and UART for communication, HDMI port and RCA jack for default TV output and 3.5mm audio socket.
The secret that makes this computer so small and powerful is the Broadcom BCM2835. A System-on-Chip that contains an ARM1176JZFS with floating point, running at 700MHz, and a Videocore 4 GPU. The GPU provides Open GL ES 2.0, hardware-accelerated OpenVG, and 1080p30 H.264 high-profile decode and is capable of 1Gpixel/s, 1.5Gtexel/s or 24 GFLOPs of general purpose compute. What’s that all mean? It means that if you plug the Raspberry Pi into your HDTV, you could watch BluRay quality video, using H.264 at 40MBits/s.
The Model B also has a 10/100 Ethernet port, You can surf the web from right there on the Pi. The system volume lives on an SD card, It’s easy to prepare, run and debug several different operating systems on the same hardware. Most Linux distributions for the Pi will happily live on 2GB SD card.
Raspberry pi Model B two built-in USB ports provide enough connectivity for a mouse and keyboard. If you want to add more you can use a USB hub. Powered hub is a good recommendation. As not to over load the on-board voltage regulator. Powering the Raspberry Pi is easy, just plug any USB power supply into the micro-USB port. The Pi will begin to boot as soon as power is applied, to turn it off simply remove power.
On top of all that, the low-level peripherals on the Pi make it great for hardware hacking. The 0.1″ spaced GPIO header on the Pi gives you access to 8 GPIO, UART, I2C, SPI as well as 3.3 and 5V sources.