The iPhone is a line of smartphones designed and marketed by Apple Inc. It runs Apple's iOS operating system and was first released in 2007. There have been several generations of iPhones released, each with improved hardware specifications like faster processors, better cameras, and larger screens. iPhones can make calls, send texts, access the internet, take photos and videos, and download third-party apps. However, Apple has faced legal battles over the iPhone trademark in some countries where it was already registered by other companies prior to Apple's use.