• An iPhone can replace a traditional cell phone, music player, PDA and camera.girl and cell phone image by starush from Fotolia.com
  
  While the features available on the iPhone vary slightly with each version of the iPhone, there are many useful and entertaining features that have remained constant through each release of this popular Apple product. The iPhone offers communication, entertainment, media and a camera in one small, portable touch-screen unit.
  
  

Cellular and Wireless

• The iPhone is, of course, a functional cellular telephone. It is also capable of sending and receiving text messages. Cellular and wireless service is available on the UMTS/HSPDA/HSUPA frequencies, as well as the GSM/EDGE frequencies. As well, it is WiFi capable and Bluetooth compatible.
  
  

Web

• The web-browsing capabilities of iPhones have been called one of the best mobile web browsers available. Phones capable of using the 3G network have access to data download speeds high enough to make watching videos online fast and easy.
  
  

Email

• After an initial set-up to allow access to your email address, a dedicated in-phone email program makes it easy to check email over the wireless network. The email browser supports Microsoft Word, Keynote, Microsoft PowerPoint and Microsoft Excel, as well as .pdf, .gif and .jpg file types, among other formats.
  
  

Memory

• The iPhone has a built-in flash-drive of up to 32GB, depending on the model chosen. Music and video files, photos, standard software and user-added apps all use up memory capacity.
  
  

iPod

• The iPhone contains an integrated iPod which is capable of playing music and videos. Media and playlists can be synced with an existing iTunes collection. The iPhone 4 can play music in AAC, MP3, AAX and WAV formats, among others. Videos and their associated audio portions are supported in .mp4, .mov, MPEG-4, M-JPEG and .avi formats.
  
  

Apps

• With more than 200,000 apps available at the time of the release of the iPhone 4, many of which cost less than three dollars or are even free, iPhone users have a wide variety of small programs called apps available to download from iTunes and install on their iPhones. Apps include photo manipulation software, language translators, cookbooks, calculators, newspaper headlines and games of every variety.
  
  

Camera

• The iPhone has a built-in still camera and, on some models, a video camera, as well as storage for recorded images. On the iPhone 4, video recording is in 720p HD quality with up to 30 frames per second with audio. The 5-megapixel camera takes VGA-quality photos and has an LED flash. Both video and still images have a tap to focus feature and both can be geotagged with the phone's built-in GPS.