When You Download a Movie From iTunes, Where Does It Go on Your Computer?by Steve Lander
ITunes is more than just a media management application. It's also a gateway to one of the world's largest media stores -- the iTunes Media Store. When you download a movie through iTunes, Apple sends the file to your computer. The iTunes program determines where it gets saved based on your configuration.
Windows File Locations
By default, iTunes creates an iTunes Media folder inside an iTunes folder in your main music folder. Unless you've changed the location where Windows saves your files, both Windows 8 and 7 use the "C:\Users\Username\My Music\iTunes\iTunes Media" directory. To find your exact path, navigate to this directory, replacing "Username" with the name you use to log into your computer. Every file iTunes downloads get sent to the iTunes Media folder.
Mac File Locations
On the Mac, iTunes works similarly. It also creates a main iTunes folder in which it creates an iTunes Media subfolder for all of your downloads. Unlike Windows, it uses a different directory scheme. To find your files on a Mac, look in Users/Username/Music/iTunes/iTunes Media. Replace "Username" with your actual username.
Moving Files and Folders
If you don't like your current storage path, you have two options. One is to pick up the downloaded movie file and move it yourself by cutting and pasting it into a new drive or directory. When you reopen the file in iTunes, the program will ask you to tell it where the new file is located. The other option is to have iTunes move its entire iTunes directory to a different location. You can do this through iTunes' Preferences tool.
Why Move Files?
By default, iTunes stores its downloaded files on your computer's main hard drive. If you have a lot of iTunes downloads as well as other material stored on your hard disk, you could run out of space quickly. Moving your iTunes files, whether you do it one at a time or in one fell swoop, conserves space on your main hard drive. This also means that you'll have room to download more movies.