Dear Lifehacker, The back of my television is a barren wasteland. I have one HDMI port in use and, beyond that, nothing else. I don't know what half of these other ports even do (e.g. why does my TV has a USB port?), but is there anything awesome I can try? Sincerely, Port Puzzled
Since the advent of HDMI, it seems that's all anyone uses now. Fortunately, there still is a place for the other ports on your television, and you can do something cool with most of them. In fact, some can be especially useful in ways you may not expect. But before we get into the probably empty ports on your television, let's just take a look at a few types of cables we're going to talk about just in case you're not familiar. If you are, just skip ahead to "The Ports" section and we'll go over what they do and the awesome things you can do with them.
RCA Composite Cables
RCA cables look like this. The yellow cable transfers a standard-definition video signal while the red and white cables handle the left and right audio channels. Technically they're all interchangeable, so you could use any colour for any purpose, but the colour-coding is mainly to make sure you connect the same colour to the same inputs and outputs.
Component RCA Cables
Component RCA cables look like this. They're basically the same as composite but there are more of them. In fact, if you have five composite RCA cables you can use them for a component connection. In this case, you still have red and white for audio, but now you have blue, red, and green for high definition video. Again, these colours are just guidelines to help you connect everything to the right input and output.
3.5mm Stereo Plug
If this looks like the end of your headphones that's because it's basically the same connector, only with a standard 3.5mm stereo plug it looks like the photo on both ends. As you've probably guessed, this is used to transfer a stereo audio signal.
VGA is what has long been used to hook up computers to their monitors. It provides an analogue signal and not a pure digital one.
DVI is a newer way to hook up your computer to a monitors. It can provide a pure digital signal (DVI-D) or an analogue signal (DVI-A). Not all cables and ports can handle both, but nowadays most can. These ports are labelled as DVI-I. Some will also provide dual-link capabilities, and this is primarily for very high resolution displays (and isn't really something you have to think about when dealing with televisions).
What It Does: If your television has a USB port, it's generally used so technicians can service your TV if it breaks. "Smart TVs" often have at least one USB port that let you plug in a hard drive, flash drive or other USB storage device to view media files on your television. If you have a TV that does this, that's pretty awesome in and of itself. If you're stuck with a service port, that's really all it's supposed to be used for.
Awesome Uses: Regardless of the suggested use of your televisions USB port, chances are it receives power. That means you can actually use it to charge USB devices, such as your smartphone or even a game controller. Although not every TV's USB port(s) will provide enough power to charge every device, you should be able to charge something. If you don't have luck with one device, try another and you may be pleasantly surprised.
What It Does: Composite ports accept a stereo audio signal (from two RCA cables) and a standard definition video signal (from a single RCA cable). This input has been around for a very long time and is the primary means of connecting standard definition sources.
Awesome Uses: While most video cameras have a variety of outputs, pretty much everything has a composite output. If you've ever gotten a still or video camera you probably have a video adaptor for it that plugs into a composite input. (It most likely looks like a headphone/3.5mm stereo cable on one end and a pair of yellow and black RCA plugs on the other.) If you want to bore your friends with slideshows or clips you can use this cable to connect your camera to your television. Alternatively, you can often send a live video feed into the television from the camera as well. This can be fun during a party, or you can use it for something more practical like a DIY security camera setup. If you have a video out port on your television (discussed later) you can even potentially record it!
What It Does: Component inputs were the first shot at sending an HD signal. Like composite, they accept RCA plugs. The difference? You have three video plugs and two audio plugs. That's about it.
Awesome Uses: If you own a Nintendo Wii, you're probably more frustrated with its standard definition-only output nowadays than you were when you bought it. While it's not going to be a phenomenal upgrade, you can get a component cable for your Wii to slightly improve the picture quality on your flatscreen and also improve the colour accuracy. Some feel it's worth the money, but it is a small improvement.
DVI and VGA
What It Does: It connects DVI and VGA sources, but the port is generally labelled "PC" because it's most often used for connecting a computer to the television. It's often paired with a 3.5mm stereo input (basically the same thing as a stereo headphone jack) so you can get audio as well.
Awesome Uses: Hooking up your computer to a television isn't awesome enough? When I want to watch videos on a friend's television I usually use this kind of hookup to do that, and the problem is solved without much hassle (aside from getting the correct VGA or DVI adaptor for the machine). But if you're not hooking up a new computer, why not an old one? VGA is a pretty old standard and many retro machines use it. You could pick one up on eBay for very little money and hook it up to your flatscreen for some old school fun.
Optical Audio / Digital Audio / TOSLINK
What It Does: A TOSLINK cable, which is more commonly referred to as an optical audio cable, sends its data via red light. It was designed to provide a pure digital audio signal rather than risk degradation from more commonly used analogue cables. These inputs are often paired with HDMI ports so you can provide a separate audio signal. Optical audio outputs are also common so you can send audio out from the TV and into a receiver that handles the multiple sources for your home theatre. When HDMI came along, it became a lot less useful as HDMI handles both audio and video, as a pure digital signal, over a single cable.
Awesome Uses: The awesome use of optical audio is optical audio itself. It provides a cleaner sound because it isn't encumbered by any noise an audio cable may otherwise generate. If you're only hooking up an audio source and you want to play it through your home theater's speaker system, optical audio is the way to go — if your device supports it, that is. You'll want to check because sometimes it's hard to tell. Optical audio is sometimes combined with a standard headphone jack and uses a variation called mini-TOSLINK to transfer the signal. This is the case with some laptops, such as Apple's MacBook Pros. If you're hooking up your optical audio-supported laptop to the television to play music for a party, for example, a mini-TOSLINK to standard TOSLINK will provide a cleaner signal.
What It Does: The video out port (and audio out port, if you have that, too) is generally a composite output (although not always) and sends whatever you've got on the television to any other source with a matching input.
Awesome Uses: Not everyone is blessed with a video out port, but if you've got one you're in for a treat. The point of a video out port is to send the video of whatever is on your television into another source. If you have a video card in your computer, you can record the output of your television. You could send that output into another video recording device to record it. What I used to do many years ago, before I cut the cable, was send the output of the television into my computer monitor which happened to face both the bathroom and the kitchen. (My apartment was small and the monitor was well-placed.) When I wanted to watch TV while cooking dinner or taking a shower, I could just switch my monitor's input to receive the television's output thanks to the wonders of the video out port. It may seem like a waste of space, but it's actually really useful when you think about it.