Apple has sold over 3 billion iPhones since its first smartphone in 2007. Samsung got there first, but there are some caveats to consider.

Apple Inc. reported its fastest quarterly revenue growth in more than three years, easily topping Wall Street estimates, after demand picked up for the iPhone and products in China.

According to Apple's recent earnings call, tariffs will add another $1.1 billion to its costs this quarter. What does that mean for you?