Let me illustrate the summarisation process for the paragraph,
The IPhone is a smartphone developed by Apple Inc. An iPhone can function as a video camera, a camera phone, a portable media player, and an Internet client with email and web browsing capabilities, can send texts and receive visual voicemail, and has both Wi-Fi and 3G connectivity. The user interface is built around the device's multi-touch screen, including a virtual keyboard rather than a physical one.
In the first stage, the input text is pre-processed to assign a meaning to each word. Words with multiple meanings - like the word "Apple" - which could stand for Apple, the fruit or Apple Inc., the company are disambiguated depending on the context of the sentence it appears in and the context of the input text.
In the adjacent figure, the word IPhone has been used to disambiguate the Apple.