iTunes purchases on multiple computers

[disco stu]

If a purchase is made through iTunes on one computer, is it in my account, or on that specific computer (hard drive)? If I switch to a new computer, will I lose the content I purchased on the previous computer?

[bartelby]

You can authorize the new computer and then unauthorize the old one.

[disco stu]

how do you "authorize" the new computer?

[telecomm]

When you try to play one of your purchased songs on the new computer you'll be prompted to enter your iTunes account password. Then that computer will be authorized to play all of the purchased music associated with that account.

[anirban]

When you try to play one of your purchased songs on the new computer you'll be prompted to enter your iTunes account password. Then that computer will be authorized to play all of the purchased music associated with that account.

And for deauthorizing, click on Store>Deauthorize Computer in iTunes.