Short Message Service: available on digital GSM networks allowing text messages of up to 160 characters to be sent and received via the network operator's message center to your mobile phone, or from the Internet, using a so-called "SMS gateway" website. If the phone is powered off or out of range, messages are stored in the network and are delivered at the next opportunity.

A software development kit (SDK or "devkit"), also known as a native developer kit (NDK) is typically a set of development tools that allows a software engineer to create applications for a certain software package, software framework, hardware platform, computer system, video game console, operating system, or similar platform.

Also known as: SMPP

Short Message Peer-to-Peer Protocol (SMPP) is the convention for how SMS messages will be exchanged between two elements, such as Short Message Service Centres.

This non-proprietary protocol is widely used, and it enables the smooth transfer of messages over the interfaces between the mobile and fixed parts of a network. This protocol also permits the sending of bulk messages from organisations to multiple subscribers.

The Subscriber Identity Module is the smart card used in digital phones containing the user’s identity for accessing the network and receiving calls. It can also store personal information, such as a phone directory and received SMS messages.

Transmission Control Protocol and Internet Protocol are in fact two cooperating protocols that are essential parts of the Internet protocol set. The TCP breaks the data into packets while the IP routes them.

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.

A video codec is the part of the software that handles converting stored digital information back to images and vice-versa. Different codecs have different capabilities, making them suitable for different applications. Regular feature phones come with a fixed set of video codecs, while the capability of smartphones to playback different codecs can usually be expanded by installing third-party solutions. The most popular mobile codecs are H.263 used in 3GP videos, H.264 in MPEG4 videos, and DivX and XviD for avi files.

WAP is an international standard for applications that use wireless communication. Its most common application is to enable access to the Internet from a mobile phone or a PDA. WAP sites are websites written in or converted to WML (Wireless Markup Language) and accessed via the WAP browser WAP websites are now considered outdated as most modern phones have web browsers with HTML support.

Wi-Fi is a WLAN (Wireless Local Area Network) technology. It provides short-range wireless high-speed data connections between mobile data devices (such as laptops, PDAs or phones) and nearby Wi-Fi access points (special hardware connected to a wired network). The most common variant of Wi-Fi is 802.11g, which is capable of providing speeds of up to 54Mbps and is backwards compatible with 802.11b (providing up to 11Mbps). There is currently a new standard in the works called 802.11n (offering twice the speeds of 802.11b) and there are already retail networking devices that support its draft specifications. Currently, there are no mobile phones that support the draft 802.11n specifications. Wi-Fi is much faster than any data technologies operating through the cellular network like GPRS, EDGE and even UMTS and HSDPA. The range covered by a Wi-Fi access point is from 30 to 100 meters indoors while outdoors a single access point can cover about 650 meters.

WiMax is the trade name for a family of new technologies related to the IEEE 802.16 wireless standards. Has the potential for very long range (up to 30 miles) and high speeds. The first versions were based on 802.16a wireless technology and designed for fixed applications only. Newer versions designed around mobility could make this a potential competitor for some 3G or 4G technologies.

XHTML (a merger of XML and HTML) is an updated HTML standard introduced to help tidy up all the developments and additions to original HTML. Over the years, different browsers added features and offered increased functionality, which all had their own proprietary manifestation in HTML. This led to a mish mash of tags and markup that often led to web authors putting in duplicate attributes and code in order to make sure that a page looked the same in different browsers browsers.

XHTML is a unifying standard from the W3C that brings the XML benefits of easy validation and troubleshooting to HTML, which not only helps developers but also makes the pages easier to read for programs such as mobile browsers.

There are three variations of XHTML, the most common of which is Transitional. XHTML Transitional is a stepping stone from the deprecated HTML standardsL, and as such is fairly permissive, allowing many old and proprietary attributes, although Transitional stipulates that all tags must have both opening and a closing markup and be correctly nested. XHTML Strict is a more rigourous standard that removes all the ’chaff’ gathered by HTML not ruled out in Transitional, and is what web authors should strive toward. Finally, XHTML Frameset is similar to XHTML Transitional, but allows for the use of frames.

Short for Extensible Markup Language, a specification developed by the W3C. XML is a pared-down version of SGML, designed especially for Web documents. It allows designers to create their own customized tags, enabling the definition, transmission, validation, and interpretation of data between applications and between organizations.