Apple TV (3rd generation) - Manual (Page 12)

12 Chapter 1 Connect. Chapter 1 Connect.
Step 1: Connecting the cables
1 Connect one end of the HDMI cable to the back of your TV.
2 Connect the other end of the cable to the HDMI port on the back of Apple TV.
3 If you’re using an optical digital audio cable for audio, connect one end of the
cable to the audio input port on your receiver or TV, and the other end to the
optical digital audio port on the back of Apple TV.
Apple TV
Television
HDMI port HDMI port
HDMI cable
Note: The built-in 802.11 Wi-Fi technology connects Apple TV to your wireless
network. If your network is Ethernet-based, connect Apple TV to your network
using an Ethernet cable.