i like the iphone,  designed and marketed by Apple Inc.
Apple is one of the leading branding companies in the world. 
Yeah iphone use Apple's iOS mobile operating system.
In the simplest terms, an operating system is what lies between you and the physical device
if i recall The first-generation iPhone was released on June 29, 2007
First announced Jan. 9, 2007, by Steve Jobs, the iPhone
IPhone
iPhone is a line of smartphones designed and marketed by Apple Inc. All generations of the iPhone use Apple's iOS mobile operating system software. The first-generation iPhone was released on June 29, 2007, and multiple new hardware iterations with new iOS releases have been released since.
The user interface is built around the device's multi-touch screen, including a virtual keyboard. The iPhone has Wi-Fi and can connect to cellular networks. An iPhone can take photos, play music, send and receive
IPadOS
iPadOS (based on iOS) is an upcoming mobile operating system created and developed by Apple Inc. Announced at Apple's 2019 Worldwide Developers Conference (WWDC), iPadOS has officially rebranded iOS on tablets to further differentiate features between the iPhone and the iPad.
History.
When the first iPad was released in 2010, it ran iPhone OS 3.2. The operating system, which had so far been used on the iPhone and iPod Touch, was rebranded as iOS with the release of iOS 4.
Since they