Use your TV as a display with Mac
Many televisions can also be used as computer displays. To connect your Mac to your television, you need a video cable that connects your computer’s display port to the video input port on your TV. If you can’t find a cable that connects the ports on your Mac and TV, you may also need an adapter for the cable.
If you have an HDTV and a Mac with a Thunderbolt port 
, Mini DisplayPort 
or HDMI port, you may also be able to play audio from your computer on your TV.
Connect your Mac to your TV
Connect one end of the video cable (or an adapter, if necessary) to the computer’s Thunderbolt port
, HDMI port or DVI port , then connect the other end of the cable to the TV’s video input port.If you need to adjust the resolution on your TV, choose Apple menu
> System Preferences, click Displays, then click Display. Select “Default for display” to automatically use the best resolution, or select Scaled to manually select a resolution.If you want your HDTV to play audio as well as video from your Mac, choose Apple menu > System Preferences, click Sound, then click Output.
Select your HDTV in the list of devices. If you want to play audio on a different device (such as your computer’s speakers or an AV receiver that’s part of your sound system), select it instead.
Note: If your Mac has a Mini DisplayPort
, make sure you use a cable (and adapter, if necessary) that supports both audio and video.
Check whether you can play audio from your Mac on your TV
If your Mac has a Mini DisplayPort, it may be able to send audio to your HDTV.
Note: If your Mac has a Thunderbolt or HDMI port, it can send audio to your HDTV.
Choose Apple menu
> About This Mac.Click Overview, then click the System Report button.
In the sidebar, below Hardware, select Audio.
A list of your computer’s audio devices appears. If HDMI Output or HDMI/DisplayPort output is listed, your computer’s Mini DisplayPort can send audio.