But everyone should have their own Apple ID. Though you might be tempted to share it with a friend or sibling so that you can share iTunes purchases, this isn't advised for a couple of reasons. First, it can makes things confusing and clutter the content in your account. And second, there's a lot of personal info in your account, and the less you share it (read: not at all), the safer it will stay. Instead, opt for a Family Sharing group. You can invite up to six members into a single group where you can all access the same iTunes, iBooks, and App Store buys. However, you probably want to limit this to actual family members, since you'll pay with the same credit card. Unless you're cool with your friend shelling out for the latest Kendrick Lamar album at a moment's notice.