Wireless HDMI kits
For general purpose wireless streaming — just using your TV as a second PC monitor, or mirroring your screen — you can purchase wireless HDMI boxes, such as the IOGEAR Wireless 3D Digital Kit.
This should allow you to connect your television to any other device that accepts an HDMI cable, with many devices offering 100 feet (30 meters) range. In other words, if your TV and PC both have an HDMI port, you can broadcast between the two without issue. If you've bought a TV or PC since about 2010, this shouldn't be an issue.
What you'll do is plug one of the boxes into your TV, and the other into your PC. Once you turn them on and set your TV to the right HDMI channel, your PC should treat the TV as a new monitor.
This might be an expensive option, but wireless HDMI boxes offer you a lot of flexibility.
Chromecasts
If you're trying to connect to the television for internet browsing purposes, then your next best bet will probably be a Chromecast. The Google Chromecast lets you broadcast content heaps of content to your TV from a PC, Mac, or mobile device.
For information on how to set up and use a Chromecast, check out our article, "'What is Google Chromecast?': How to use Google's smart device for TVs and monitors."
Game streaming devices
If you're trying to wirelessly connect for PC gaming purposes, you should look into devices like the Steam Link. The Link allows you to stream video games from your PC to a TV wirelessly over Wi-Fi, or with an ethernet cable.
All you need to do is plug the Link into your TV, and connect it to the same internet network as your PC. Once you've done that, you can stream nearly any Steam game to your PC.
The NVIDIA Shield can do the same thing, and lets you play any PC game, even if they're not on Steam. But it comes with a hefty price tag — nearly $200 for the gaming edition.
Related coverage from How To Do Everything: Tech:- How to connect your Mac computer to a TV, and use a TV as a mirrored screen or second monitor
- How to connect an iPhone to your LG Smart TV with a free third-party app, to mirror and stream content between devices
- How to connect your iPhone to a TV in two different ways
- How to connect an iPad to your TV in two different ways