Apple iPhone SE 

The iPhone SE is a smartphone designed and marketed by Apple Inc. as part of the iPhone series of devices. It was unveiled on March 21, 2016, at Apple'sCupertino headquarters and was released on March 31, 2016. It serves as a replacement for iPhone 5S as a lower-cost entry in the iPhone product line; combining the updated processor, rear camera, and other features from the high-end iPhone 6S with the smaller 4-inch display and nearly identical styling to the iPhone 5S, the only differences being the available colors (similar to the iPhone 6S models) and the matte chamfered edges.
The iPhone SE is available in silver, "space-gray", gold, and rose-goldfinishes, and are priced at US$399 for 16 GB and US$499 for 64 GB in theUnited States.

The last major redesign of iPhone, the 4.7/5.5-inch iPhone 6 and 6 Plus, resulted in larger screen sizes. However, there were still a significant number of customers who preferred the 4-inch screen size of iPhone 5 and 5S; the 5S was the second-most popular iPhone after the 6, ahead of the 6S. Apple stated in their event that they sold 30 million 4-inch iPhones in 2015. Furthermore, the 5 and 5S design was regarded as "long been the golden child of Apple phone design and a benchmark for phones in general," while the succeeding 6 and 6S design was less critically acclaimed as it "felt a little bit wrong, as though you were holding a slick $650 bar of soap." iPhone 5 was described as "elegance rooted in the way the aluminum and glass work together. It felt streamlined, yet substantial, which is different from iPhone 6, which feels substantial in size alone. Plus, unlike the ubiquitous rounded corners of the 6, iPhone 5 didn’t really look like anything else on the market at the time."
Apple's product positioning trend (in North America and Western Europe), starting with iPhone 4S released in October 2011, gave each newly released model one year as the flagship phone, then moving it to midrange for its second year of production, with the third and final year as the entry-level offering before discontinuation. While iPhone 5S was expected to continue on sale until September 2016, replacing it and its A7 processor early means that Apple "just reduced its long-term chip support window by a year" for iOS. In addition, a new iPhone launch was meant to stimulate demand, as sales of iPhone 6S and 6S Plus had not met expectations since their September 2015 release and the iPhone family may suffer its first ever negative growth quarter in 2016.