The iPhone 4 represented the first major redesign of the iPhone since its launch in 2007. It had a thinner profile and a sharper shape compared to its predecessors, featuring a body made of glass with a stainless steel trim that wrapped around its edges.
It also introduced the Retina display, which has become a hallmark of Apple's products ever since, and was the first iPhone to come with FaceTime video calling.
While the iPhone 4 was generally well-received, it wasn't immune to its fair share of criticism, most notably because of a call reception issue that became known as "Antennagate." Some iPhone 4 owners experienced frequent dropped calls due to an issue with the antenna when the phone was held a certain way, a problem that prevented Consumer Reports from recommending it in 2010.