The Adruino is built around the 8-bit Atmel AVR microcontroller line. It also exposes numerous digital, PWM, and analog pins for easy hookup to external devices. It is in no way a general use computer.
The Raspberry PI has a 32-bit ARM chip that can run Linux. It has a video output, USB for keyboard and mouse, and one version has an Ethernet port. It's aim is to make a cheap general purpose Linux system.
The Raspberry PI has a 32-bit ARM chip that can run Linux. It has a video output, USB for keyboard and mouse, and one version has an Ethernet port. It's aim is to make a cheap general purpose Linux system.