Coax Digital Audio (S/PDIF) – This offers digital connection with copper cables, most generally Coax. Cables are long. And Dolby Digital 5.1, 7.1, DTS etc. is supported. However, the copper cables mess with run into interference. Neither DVD-A or SACD are supported.

Firewire – This offers digital connection with large bandwidth, multichannel audio. Highly compatible and choice for some HTPCs, new receivers, STB's, DVD's and with Digital Audio Workstations; and may have some support for DVD-A and SACD. However, lacks locking connector, also disconnects easily; so audio-only interface is main reason for use with a lot of systems at this time, except for use with Set Top Boxes, audio and video with camcorder use, HDTV's and Digital VCR's.

Toslink - This offers digital connection without electrical interference, great for digital audio signals with compatible equipment; Digital Cable / DVD/Satellite Receiver with Toslink connector compat. Dolby Digital 5.1, 7.1, DTS etc. However, cable length is limited, the cables aren't sturdy and they disconnect too quickly and easily. You will need fiber optic cables or repeaters for lengthy cable reaches. Neither is there is any DVD-A or SACD support, nor locking connector.

HDMI – This offers a digital connection with great quality electrical interface transmitting up to 1080p video plus 8 channels of 192kHz audio. Great with both digital audio and video via one interface. However, they lack locking connectors and easily disconnect.

Stereo – Features analog audio, with dual RCA plug cables usually, and two channels, left and right. If your equipment is not compatible with digital audio, analog stereo is next choice. However, this lacks surround sound, unless simulated.

Denon Link - DL3 of SACD combined with DVD-A. However, only comes with Denon goods.

Mono – you don't want this, forget about it!

So check out your own equipment and system compatibility. There are many types of audio cables for your home theater system. And you want to select the best for your home theater experience and enjoyment.