basic telephony. handsets with more advanced computing ability through the use of native software applications are known as smartphones. central processing unit mobile phones have central processing units (cpus), similar to those in computers, but optimised to operate in low power environments. mobile cpu performance depends not only on the clock rate (generally given in multiples of hertz) but also the memory hierarchy also greatly affects overall performance. because of these problems, 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 phones is the screen. depending on the device's type and 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 often measured in diagonal inches or millimeters; feature phones generally have screen sizes below 90 millimetres (3.5 in). phones with screens larger than 130 millimetres (5.2 in) are often called "phablets." smartphones with screens over 115 millimetres (4.5 in) 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 are the most common; others are ips, led, oled, and amoled displays. some displays are integrated with pressure-sensitive digitizers, such as those developed by wacom and samsung, and apple's "3d touch" system. sound in sound, smartphones and feature phones vary little. 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 the average phone battery lasts 2–3 years at best. many of the wireless devices use a lithium-ion (li-ion) battery, which charges 500–2500 times, depending on how users take care of the battery and the charging techniques used. it is only natural for these rechargeable batteries to chemically age, which is why the performance of the battery when used for a year or two will begin to deteriorate. battery life can be extended by draining it regularly, not overcharging it, and keeping it away from heat. sim card typical mobile phone mini-sim card mobile phones require a small microchip called a subscriber identity module or sim card, in order to function. the sim card is approximately the size of a small postage stamp and is usually placed underneath the battery in the rear of the unit. the sim securely stores the service-subscriber key (imsi) and the ki used to identify and authenticate the user of the mobile phone. the sim card allows users to change phones by simply removing the sim card from one mobile phone and inserting it into another mobile phone or broadband telephony device, provided that this is not prevented by a sim lock. the first sim card was made in 1991 by munich smart card maker giesecke & devrient for the finnish wireless network operator radiolinja. a hybrid mobile phone can hold up to four sim cards, with a phone having a different device identifier for each sim card. sim and r-uim cards may be mixed together to allow both gsm and cdma networks to be accessed. from 2010 onwards, such phones became popular in emerging markets, and this was attributed to the desire to obtain the lowest calling costs. when the removal of a sim card is detected by the operating system, it may deny further operation until a reboot. software software platforms android smartphones feature phones have basic software platforms. smartphones have advanced software platforms. android os has been the best-selling os worldwide on smartphones since 2011. mobile app main article: mobile app a mobile app is a computer program designed to run on a mobile device, such as a smartphone. the term "app" is a shortening of the term "software application". messaging a text message (sms) a common data application on mobile phones is short message service (sms) text messaging. the first sms message was sent from a computer to a mobile phone in 1992 in the uk while the first person-to-person sms from phone to phone was sent in finland in 1993. the first mobile news service, delivered via sms, was launched in finland in 2000, and subsequently many organizations provided "on-demand" and "instant" news services by sms. multimedia messaging service (mms) was introduced in march 2002. application stores the introduction of apple's app store for the iphone and ipod touch in july 2008 popularized manufacturer-hosted online distribution for third-party applications (software and computer programs) focused on a single platform. there are a huge variety of apps, including video games, music products and business tools. up until that point, smartphone application distribution depended on third-party sources providing applications for multiple platforms, such as getjar, handango, handmark, and pocketgear. following the success of the app store, other smartphone manufacturers launched application stores, such as google's android market (later renamed to the google play store), rim's blackberry app world, or android-related app stores like aptoide, cafe bazaar, f-droid, getjar, and opera mobile store. in february 2014, 93% of mobile developers were targeting smartphones first for mobile app development. sales by manufacturer market share of top-five worldwide mobile phone vendors, q2 2022 rank manufacturer strategy analytics report 1samsung21% 2apple16% 3xiaomi13% 4oppo10% 5vivo9% others31% note: vendor shipments are branded shipments and exclude oem sales for all vendors. as of 2022, the top five manufacturers worldwide were samsung (21%), apple (16%), xiaomi (13%), oppo (10%), and vivo (9%). history from 1983 to 1998, motorola was market leader in mobile phones. nokia was the market leader in mobile phones from 1998 to 2012. in q1 2012, samsung surpassed nokia, selling 93.5 million units as against nokia's 82.7 million units. samsung has retained its top position since then. aside from motorola, european brands such as nokia, siemens and ericsson once held large sway over the global mobile phone market, and many new technologies were pioneered in europe. by 2010, the influence of european companies had significantly decreased due to fierce competition from american and asian companies, to where most technical innovation had shifted. apple and google, both of the united states, also came to dominate mobile phone software. by mobile phone operator the world's largest individual mobile operator by number of subscribers is china mobile, which has over 902 million mobile phone subscribers as of june 2018. over 50 mobile operators have over ten million subscribers each, and over 150 mobile operators had at least one million subscribers by the end of 2009. in 2014, there were more than seven billion mobile phone subscribers worldwide, a number that is expected to keep growing. use mobile phone subscribers per 100 inhabitants. 2014 figure is estimated. mobile phones are used for a variety of purposes, such as keeping in touch with family members, for conducting business, and in order to have access to a telephone in the event of an emergency. some people carry more than one mobile phone for different purposes, such as for business and personal use. multiple sim cards may be used to take advantage of the benefits of different calling plans. for example, a particular plan might provide for cheaper local calls, long-distance calls, international calls, or roaming. the mobile phone has been used in a variety of diverse contexts in society. for example: a study by motorola found that one in ten mobile phone subscribers have a second phone that is often kept secret from other family members. these phones may be used to engage in such activities as extramarital affairs or clandestine business dealings. some organizations assist victims of domestic violence by providing mobile phones for use in emergencies. these are often refurbished phones. the advent of widespread text-messaging has resulted in the cell phone novel, the first literary genre to emerge from the cellular age, via text messaging to a website that collects the novels as a whole. mobile telephony also facilitates activism and citizen journalism. the united nations reported that mobile phones have spread faster than any other form of technology and can improve the livelihood of the poorest people in developing countries, by providing access to information in places where landlines or the internet are not available, especially in the least developed countries. use of mobile phones also spawns a wealth of micro-enterprises, by providing such work as selling airtime on the streets and repairing or refurbishing handsets. in mali and other african countries, people used to travel from village to village to let friends and relatives know about weddings, births, and other events. this can now be avoided in areas with mobile phone coverage, which are usually more extensive than areas with just land-line penetration. the tv industry has recently started using mobile phones to drive live tv viewing through mobile apps, advertising, social tv, and mobile tv. it is estimated that 86% of americans use their mobile phone while watching tv. in some parts of the world, mobile phone sharing is common. cell phone sharing is prevalent in urban india, as families and groups of friends often share one or more mobile phones among their members. there are obvious economic benefits, but often familial customs and traditional gender roles play a part. it is common for a village to have access to only one mobile phone, perhaps owned by a teacher or missionary, which is available to all members of the village for necessary calls. content distribution in 1998, one of the first examples of distributing and selling media content through the mobile phone was the sale of ringtones by radiolinja in finland. soon afterwards, other media content appeared, such as news, video games, jokes, horoscopes, tv content and advertising. most early content for mobile phones tended to be copies of legacy media, such as banner advertisements or tv news highlight video clips. recently, unique content for mobile phones has been emerging, from ringtones and ringback tones to mobisodes, video content that has been produced exclusively for mobile phones. mobile banking and payment mobile payment system in many countries, mobile phones are used to provide mobile banking services, which may include the ability to transfer cash payments by secure sms text message. kenya's m-pesa mobile banking service, for example, allows customers of the mobile phone operator safaricom to hold cash balances which are recorded on their sim cards. cash can be deposited or withdrawn from m-pesa accounts at safaricom retail outlets located throughout the country and can be transferred electronically from person to person and used to pay bills to companies. branchless banking has also been successful in south africa and the philippines. a pilot project in bali was launched in 2011 by the international finance corporation and an indonesian bank, bank mandiri. mobile payments were first trialled in finland in 1998 when two coca-cola vending machines in espoo were enabled to work with sms payments. eventually, the idea spread and in 1999, the philippines launched the country's first commercial mobile payments systems with mobile operators globe and smart. some mobile phones can make mobile payments via direct mobile billing schemes, or through contactless payments if the phone and the point of sale support near field communication (nfc). enabling contactless payments through nfc-equipped mobile phones requires the co-operation of manufacturers, network operators,