What do Black Friday deals for cell phones mean when they say, . With activation? (read details)?

What if i already have an account with at&t and i want to get an iphone with at&t? Is it saying i have to get a new plan in order to get the deal or i just have to get a new sim card? Sorry if this is a dumb question, i just want to be sure about it.

"With activation" means you would have to sign up with the carrier in question (or if you have a contract with them already renew)

If you read "with activation" as "with new contract" that should clear things up. That could be adding a second line, or replacing the current phone, as long as you take on a new 2-year contract so they can recover the cost of discounting the phone.