Ethernet is the local area network most used nowadays.
Usual Arduino boards don't provide Ethernet ability. There is one board named Arduino Ethernet that provides native Ethernet and network features. By the way, it doesn't provide any USB-native features.
You can find the reference page here: http://arduino.cc/en/Main/ArduinoBoardEthernet.
We are going to use the Arduino Ethernet Shield and a 100BASE-T cable with the Arduino UNO R3. It keeps the USB features and adds Ethernet network connectivity and provides a nice way to link our computer to the Arduino with a much ...