You have a Mac and an Apple TV, but sometimes you want to watch your movies and TV shows on your iPad. How do you do that without syncing videos to your iPad? It's pretty easy once you enable Home Sharing.
To enable Home Sharing on your computer, launch iTunes, the go to File > Home Sharing > Turn on Home Sharing. Enter your Apple ID when asked. If you use an Apple TV, Home Sharing is probably already enabled. To enable Home Sharing on your iPad, tap Settings, select Music, then enter the same Apple ID in the Home Sharing fields.
With Home Sharing enabled, you can see your computer's iTunes video library...
To stream TV shows and movies to your iPad first make sure iTunes is running on your computer, and that your computer and iPad are on the same network. Now tap the Videos app on your iPad, then tap the Shared tab. Next, select your iTunes library to see the videos that are available from your computer.
...and choose videos to stream to your iPad.
Home sharing groups videos into Movies, TV Shows, and Music Video categories, so tap the tab for the type of video you want to watch. Next, select the video you want to watch, and sit back and enjoy.
You can stream videos to your iPhone or iPod touch, and streaming works for music in the iTunes app, too.
I use Home Sharing to stream videos from my Mac to my iPad when I don't feel like sitting in front of the television. It's also really handy when I come up against weird problems like a TV show that plays fine on my Mac, but has audio that sounds like hissing on my Apple TV. I'm not big on sitting at my computer to watch shows, so streaming to my iPad from the couch is a much better option for me.