User Interface is the software front for interacting with the technical features of a mobile phone. Although the term can also be used for hardware input such as controls or keys, in the area of mobile phones it's most frequently used to refer to the software-controlled elements displayed on the screen that are used to interact with the device. That includes icons in the menus, text boxes, etc. User Interfaces that are easier to use than others are referred to as more user-friendly.

Unlicensed Mobile Access Provides access to voice and data services over unlicensed spectrum technologies like Wi-Fi or BlueTooth. UMA phones automatically switch between cellular networks and local networks when in range. VOIP - Voice over Internet Protocol is a protocol optimized for the transmission of voice through the Internet or other packet switched networks. Also known as IP Telephony, Internet telephony, Broadband telephony, Broadband Phone and Voice over Broadband.

A 16-bit character encoding scheme allowing characters from Western European, Eastern European, Cyrillic, Greek, Arabic, Hebrew, Chinese, Japanese, Korean, Thai, Urdu, Hindi and all other major world languages, living and dead, to be encoded in a single character set. The Unicode specification also includes standard compression schemes and a wide range of typesetting information required for worldwide locale support. Symbian OS fully implements Unicode.

Android uses URI strings both for requesting data (e.g., a list of contacts) and for requesting actions (e.g., opening a Web page in a browser). Both are valid URI strings, but have different values. All requests for data must start with the string "content://". Action strings are valid URIs that can be handled appropriately by applications on the device; for example, a URI starting with "http://" will be handled by the browser.