Hardware

A typical smartphone contains a number of metal–oxide–semiconductor (MOS) integrated circuit (IC) chips, which in turn contain billions of tiny MOS field-effect transistors (MOSFETs). A typical smartphone contains the following MOS IC chips.

• Application processor (CMOS system-on-a-chip)
• Flash memory (floating-gate MOS memory)
• Cellular modem (baseband RF CMOS)
• RF transceiver (RF CMOS)
• Phone camera image sensor (CMOS image sensor)
• Power management integrated circuit (power MOSFETs)
• Display driver (LCD or LED driver)
• Wireless communication chips (Wi-Fi, Bluetooth, GPS receiver)
• Sound chip (audio codec and power amplifier)
• Gyroscope
• Capacitive touchscreen controller (ASIC and DSP)
• RF power amplifier (LDMOS)
• A hardware notification LED on some phones

Central processing unit

Smartphones have central processing units (CPUs), similar to those in computers, but optimised to operate in low power environments. In smartphones, the CPU is typically integrated in a CMOS (complementary metal–oxide–semiconductor) system-on-a-chip (SoC) application processor.

The performance of mobile CPU depends not only on the clock rate (generally given in multiples of hertz) but also on the memory hierarchy. Because of these challenges, the performance of mobile phone CPUs is often more appropriately given by scores derived from various standardized tests to measure the real effective performance in commonly used applications.

Display

One of the main characteristics of smartphones is the screen. Depending on the device's design, the screen fills most or nearly all of the space on a device's front surface. Many smartphone displays have an aspect ratio of 16:9, but taller aspect ratios became more common in 2017.

Screen sizes are measured in diagonal inches. Phones with screens larger than 5.2 inches are often called "phablets". Smartphones with screens over 4.5 inches in size are commonly difficult to use with only a single hand, since most thumbs cannot reach the entire screen surface; they may need to be shifted around in the hand, held in one hand and manipulated by the other, or used in place with both hands. Due to design advances, some modern smartphones with large screen sizes and "edge-to-edge" designs have compact builds that improve their ergonomics, while the shift to taller aspect ratios have resulted in phones that have larger screen sizes whilst maintaining the ergonomics associated with smaller 16:9 displays.

Liquid-crystal displays (LCDs) and organic light-emitting diode (OLED) displays are the most common. Some displays are integrated with pressure-sensitive digitizers, such as those developed by Wacom and Samsung, and Apple's Force Touch system.

Sound

Some audio quality enhancing features, such as Voice over LTE and HD Voice have appeared and are often available on newer smartphones. Sound quality can remain a problem due to the design of the phone, the quality of the cellular network and compression algorithms used in long-distance calls. Audio quality can be improved using a VoIP application over WiFi. Cellphones have small speakers so that the user can use a speakerphone feature and talk to a person on the phone without holding it to their ear. The small speakers can also be used to listen to digital audio files of music or speech or watch videos with an audio component, without holding the phone close to the ear.

Battery

A smartphone typically uses a lithium-ion battery. By the end of 2017, smartphone battery life has become generally adequate; however, earlier smartphone battery life was poor due to the weak batteries that could not handle the significant power requirements of the smartphones' computer systems and color screens.

Smartphone users purchase additional chargers for use outside the home, at work, and in cars and by buying portable external "battery packs". External battery packs include generic models which are connected to the smartphone with a cable, and custom-made models that "piggyback" onto a smartphone's case. In 2016, Samsung had to recall millions of the Galaxy Note 7 smartphones due to an explosive battery issue. For consumer convenience, wireless charging stations have been introduced in some hotels, bars, and other public spaces.

Cameras

Cameras have become standard features of smartphones. As of 2019 phone cameras are now a highly competitive area of differentiation between models, with advertising campaigns commonly based on a focus on the quality or capabilities of a device's main cameras.

Typically smartphones have at least one main rear-facing camera and a lower-resolution front-facing camera for "selfies" and video chat. Owing to the limited depth available in smartphones for image sensors and optics, rear-facing cameras are often housed in a "bump" that's thicker than the rest of the phone. Since increasingly thin mobile phones have more abundant horizontal space than the depth that is necessary and used in dedicated cameras for better lenses, there's additionally a trend for phone manufacturers to include multiple cameras, with each optimized for a different purpose (telephoto, wide angle, etc.).

Images are usually saved in the JPEG file format; some high-end phones also have RAW image capability.

Modern advanced smartphones have cameras with optical image stabilisation (OIS), larger sensors, bright lenses, and even optical zoom plus RAW images. HDR, "Bokeh mode" with multi lenses and multi-shot night modes are now also familiar. Many new smartphone camera features are being enabled via computational photography image processing and multiple specialized lenses rather than larger sensors and lenses, due to the constrained space available inside phones that are being made as slim as possible.

Accessories

A wide range of accessories are sold for smartphones, including cases, screen protectors, power charging cables, wireless power stations, USB On-The-Go adapters (for connecting USB drives and or, in some cases, a HDMI cable to an external monitor), add-on batteries, headphones, combined headphone-microphones (which, for example, allow a person to privately conduct calls on the device without holding it to the ear), and Bluetooth-enabled powered speakers that enable users to listen to media from their smartphones wirelessly.

Cases range from relatively inexpensive rubber or soft plastic cases which provide moderate protection from bumps and good protection from scratches to more expensive, heavy-duty cases that combine a rubber padding with a hard outer shell. Some cases have a "book"-like form, with a cover that the user opens to use the device; when the cover is closed, it protects the screen. Some "book"-like cases have additional pockets for credit cards, thus enabling people to use them as wallets.

Accessories include products sold by the manufacturer of the smartphone and compatible products made by other manufacturers.