Although it has the primary functions of a mobile phone,it delights the public with things such as Wi-Fi implemented technology,Web-Browsing e-mail,as well as the possibility to be used as a portable media player (this includes movies,music and pictures).The old and common control keyboard was replaced by a next-generation multi touch-screen displays that also possesses digital keys.The iPhone supports third-party applications that can be found on Apple's official online store(App Store) since 2008 when it was opened.Since then,the store has over 20.000 applications in its database.In order for an application to work,it needs to be approved by Apple.
Applications may refer to games,social networking,movies,celebrities,music,GPS,and menu others from many categories.There are four iPhone models available and each model also announced the appearance of a new iOS(originaly called iPhone OS). The second version,the iPhone 3G added 3G cellular functions.The third installment(iPhone 3GS)added a compass and higher resolution for the screen and faster processor.The iPhone 4 (the fourth installment) was released in 2010 and has two camera for Face-Time calls,as well as higher display-screen resolution.
Although each model arrived with some updates and upgrades,all kept essential things from the first iPhone,like button positioning and screen-size. The screen is scratch resistant and measures 9cm(3.5 inch).It was designed for bare finer touch,as well as multi-touch,for performing tasks by using several fingers in the same time,like when zooming in or out a picture.The touch-screen technology iPhones work on were originally developed by a company named Finger Works,and didn't support some styluses or gloves,as electrical connectivity wasn't high enough.
The hardware user interface on the iPhone is minimal,as they are few physical buttons available.The first button is called "Home Button".It is called that way because pressing it will make the iPhone automatically close every open application at that time and redirect the user to the main screen,or home screen,where are the device's application are available for use.Although it is named "home button" the icon on the button does not represent a house as many other phones do,but a small rounded square which is the same shape of the apps that the iPhone has.
The second button is on top of the phone and serves as a multifunction sleep/wake button which acts as the power button when the iPhone is closed,and it can silence the ringtone and redirect to voicemail during calls.The other physical buttons present are the volume keys,located on the side.The iPhone 4's volume keys are displayed under separate plastic covers,as earlier versions had the volume keys under the same plastic.