Cupertino , California ( CNN ) -- Apple on Tuesday unveiled the iPhone 4S , a faster version of its best-selling smartphone that includes a virtual `` personal assistant '' you can talk to . `` When you think about it , only Apple could make such amazing software , hardware and services and bring them together into such a powerful yet integrated experience , '' the company 's new CEO Tim Cook said at a press conference Tuesday at the company 's headquarters in Cupertino , California . The next-generation iPhone also will be available on Sprint 's wireless network for the first time , in addition to AT & T and Verizon . A model with 16 GB of storage starts at $ 200 with a two-year wireless contract ; the 64 GB model costs $ 400 . An online presale for the phone begins on Friday , and the phone will become available in stores on October 14 . Steve Jobs , the Apple co-founder who recently resigned as CEO amid health concerns , did not take the stage at the press conference and was not seen by CNN reporters at the event . The iPhone 4S looks identical to a previous model , but it contains an A5 processor that the company says is up to seven times faster at rendering graphics and twice as fast at processing data . It has a personal assistant called `` Siri , '' which takes voice commands and can translate speech into text . Siri also talks back , answering questions and reading calendar events and updates . `` I 've been in the AI ( artificial intelligence ) field a long time . This blows me away , '' Apple 's Scott Forstall , a senior vice president for iPhone software , said after he announced the new service , which only works on the iPhone 4S , not on previous models . In a demo , Forstall asked the phone to `` find me a Greek restaurant in Palo Alto . '' The phone pulled up restaurants from the app Yelp and said : `` I have found 14 Greek restaurants ; five of them are in Palo Alto . I have listed them according to ranking . '' Some people who followed the event online joked that Siri reminded them of the computer HAL from the movie , `` 2001 : A Space Odyssey . '' `` We are clearly headed to Terminator/HAL territory here . Humans are doomed . Deal with it , '' wrote Sam Grobart on the New York Times ' live blog of the press conference . The voice feature also pulls data from Wikipedia and search engine WolframAlpha , among other information services . The iPhone 4S is also a `` world phone , '' meaning it will be able to place calls more easily on wireless networks all over the world , not just in the United States . Among the other updates : . -- The phone also has `` fantastic battery life , '' allowing people to talk for eight hours before needing to charge it again , said Phil Schiller , Apple 's vice-president for product marketing . -- It features an 8-megapixel camera with a better light sensor , making it as good or better than many point-and-shoot devices . -- It will shoot high-definition video , and it has a new image stabilization feature to make YouTube videos less shaky . Despite some new features , however , some market analysts were disappointed that Apple did not release a more radically designed version of its smartphone , as CNNMoney reports . Apple 's shares sagged slightly for the day on news of the phone 's update . At the event on Tuesday , Apple also announced updates to its mobile operating system , called iOS5 , which will be available for free on October 12 . The new version of the operating system works on the iPhone 4 and 3GS , as well as both versions of the iPad and the iPod Touch . The iOS 5 system includes several new features , including a cloud service that will sync some photos and files from the iPhone onto Internet servers . A product called iTunes Match will sync music from the iPhone with a database in the cloud , making it possible to play your music on any device or computer instead of just on the one where you purchased it . The iTunes Match product will be available later this month , the company said , and costs $ 25 per year . A new app called Cards will let iPhone owners send paper greeting cards to people for a fee that includes postage . And , finally , a new social networking app called Find My Friends lets users share their current location with close contacts . In all , Apple says it has sold 250 million gadgets that run on its mobile operating system . The company finds itself as the top mobile gadget maker . The iPhone 4 and the iPhone 3GS were the best-selling smartphone models in the United States in the second quarter of this fiscal year , according to data from the NPD Group . Apple says it sold more than 20 million iPhones in the last financial quarter alone , up 142 % from that same period of time in 2010 . Cook on Tuesday said the iPhone is the bestselling phone in the world . We 'll have to wait a few weeks to see how well the iPhone 4S continues that success .
Apple iPhone 4S is faster than previous versions . It has enhanced voice-recognition features . iPhone up to seven goes on sale starting at $ 400 on later this month . For the first time , it 's available on Verizon as well as AT & T and Sprint .