iPhone hardware
The iPhone 6S and 6S Plus, introduced in 2015, feature 3D Touch displays which allow the screen to recognize how hard it is being pressed using pressure-sensitive multi-touch technology, and a new Taptic Engine to provide haptic feedback.
[9] In addition to visual cues, 3D Touch uses the Taptic Engine to provide a tactile sensation relative to the force being applied to the display to indicate to the user that a light or deep press action has been completed.
iPhones feature a number of sensors, which are used to adjust the screen based on operating conditions, enable motion-controlled games, location-based services, unlock the phone, and authenticate purchases with Apple Pay, among many other things.
[12] The iPhone's proximity sensors detect the ear and switches off the light, saving power and stopping the face from unintentionally pressing buttons.
[14] True Tone, which is activated by default, uses advanced sensors to change the colour and intensity of the iPhone screen to match the ambient light, resulting in more natural-looking images.
The device changes the screen brightness automatically based on this knowledge to save battery life and minimize eye strain.
[15] A 3-axis accelerometer senses the orientation of the phone and changes the screen accordingly, allowing the user to easily switch between portrait and landscape mode.
The 3.0 update added landscape support for still other applications, such as email, and introduced shaking the unit as a form of input (generally for undo functionality).
[21] This sensor is used to provide position and navigational features by determining the altitude through evaluating air pressure.
While non-sanctioned third-party solutions exist, the iPhone does not officially support the OBEX file transfer protocol.
[29] The lack of these profiles prevents iPhone users from exchanging multimedia files, such as pictures, music and videos, with other Bluetooth-enabled cell phones.
Apple's website says that the battery life "is designed to retain up to 80% of its original capacity after 500 complete charge cycles".
[35] The battery life of early models of the iPhone has been criticized by several technology journalists as insufficient and less than Apple's claims.
[36][37][38][39] This is also reflected by a J. D. Power and Associates customer satisfaction survey, which gave the "battery aspects" of the iPhone 3G its lowest rating of two out of five stars.
[40][41] If the battery malfunctions or dies prematurely, the phone can be returned to Apple and replaced for free while still under warranty.
These changes came in the wake of reported issues with unexpected shutdowns on certain iPhone models following the release of iOS 10.1.1.
In response to criticism over the practice, including concerns over this being a form of planned obsolescence, Apple announced that it would offer discounted battery replacements for iPhone 6 and newer in 2018, and that it would add additional battery health information on a future version of iOS (iOS 11.3, which also allows users to disable this throttling).
It also has a backside-illuminated sensor that can capture pictures in low light and an LED flash that can stay lit while recording video.
[56] In 2014, Apple consumed "one-fourth of the world’s supply of sapphire to cover the iPhone’s camera lens and fingerprint reader.
Its image sensor is now 15 percent larger (1/3") than its previous model (1/3.2") at the same resolution to increase the surface size of individual pixels, allowing them to capture more light in the same time.
[60] With the release of iOS 8, the iPhone 4S and later models can now shoot time-lapse videos, with its capability to switch frame rates automatically as the recording increases its time.
[26][64] It also has a brighter quad-LED True Tone flash The 2017 iPhone 8 camera features a larger sensor and a newer color filter.
It also features Smart HDR, using the power of A12 Bionic chip, along with the Neural Engine, machine learning, artificial intelligence, and some advancements to provide better photos with improved dynamic range.
The front camera is now capable of recording video at 4K as a result of a new 12 MP sensor, and can also capture slow-motion footage.
[74][75] Some iPhone models shipped with a SIM ejector tool which was fabricated from an alloy dubbed "Liquidmetal".
iPhone 14 and 14 Pro and later models sold in the United States do not have the SIM card slot, and instead only supports eSIM.
The first generation iPhone includes a stereo headset (earbuds and a microphone) and a plastic dock to hold the unit upright while charging and syncing.
The iPhone 3G includes a similar headset plus a SIM eject tool (the first generation model requires a paperclip).
[88] All versions include a USB power adapter, or "wall charger", which allows the iPhone to charge from an AC outlet.
The feature, aimed to "revolutionize" the way users pay, uses an NFC chip, Touch ID fingerprint scanner (Face ID on iPhone X and later), Apple's Wallet app, and a dedicated "Secure Element" chip for encrypted payment information to make purchases at participating stores, both physical and online.
