Symbian

Symbian Ltd is the software firm that develops and licenses the Symbian OS. Originally spun off from Psion, a maker of PDA devices, the company now focuses on its operating system products. The company is jointly owned by Nokia, Ericsson, Matsushita (AKA Panasonic), Siemens, Sony Ericsson, and Samsung. Motorola was previously a shareholder, but it sold its shares to Psion and Nokia. Nokia later acquired Psion's shares and is now the largest shareholder in the company.

Memory Stick Duo

Memory Stick Duo is a small flash memory card format developed by Sony and based on the original Memory Stick format. An updated version, Pro Duo, was later released that allowed for larger capacities and faster transfer rates than the original. Duo and Pro Duo cards measure 31mm x 20mm in size.

LCD (Liquid Crystal Display)

A liquid crystal display, typically referred to as an LCD, is a flat display technology that uses electrodes and polarizing filters to selectively enable or disable pixels of light to pass from a backlight or reflective backing to the eyes of the viewer. Color displays have 3 such sites per pixel, each with a red, green, or blue color filter, which allows the display to create any number of colors. Most LCD displays used with mobile phones are of the active matrix variety, but some older displays still make use of passive matrix designs. In the future, LCD technology might be displaced in mobile devices by OLED display technology.

Java

Java is an object oriented programming language developed by Sun Microsystems that allows compiled applications to be run on many different and otherwise incompatible platforms through the use of a Java compatible engine developed for each specific platform. Java's mantra is "Write once, run anywhere", which is largely true. Various levels of device capabilities exist, though, requiring the creation of the MIDP 1 and MIDP 2 Java profiles. MIDP 2 applications, which are more powerful, will not run on a MIDP 1 device.

IMAP (Internet Message Access Protocol)

The Internet Message Access Protocol is a network protocol that allows a compatible mail client to access email messages and message folders that are stored on a central mail server. Unlike POP3, which retrieves messages from the server to be read, IMAP clients leave the actual message stored on the server. Additionally, an IMAP server tracks the state of a given message, so that a message that is read and responded to on a mobile device will show on a desktop client as having been read and responded to. This advantage is why IMAP is often used by business users and those that make use of mobile devices to read email. Version 4 of the IMAP protocol is the one most commonly in use today.

IMEI (International Mobile Equipment Identity)

An IMEI is a serial number that uniquely identifies a GSM or UMTS mobile phone. Typically 15 digits long, the IMEI code is broken into sections that provide information about a phone, such as its manufacturer, to the mobile network that the phone is connected to. IMEI numbers of stolen devices are blacklisted in some countries so that the phone can not easily be used by a thief. CDMA's new MEID identifier system is compatible with the existing IMEI structure.

GPS (Global Positioning System)

The Global Positioning System is a series of satellites owned by the US government that broadcasts signals that GPS receivers on the surface of the planet can use to determine position through triangulation. The term GPS is often used to refer to a GPS receiver, such as those used in cars and sometimes found in mobile phones.

GPRS (General Packet Radio Service)

GPRS is a wireless data standard used on GSM networks. It offers theoretical data rates as high as 120kbps on the downlink side, but real world speeds are typically significantly slower.

UMA (GAN, Generic Access Network, Unlicensed Mobile Access)

Unlicensed Mobile Access is a technology that allows a UMA capable mobile phone to seamlessly switch back and forth between mobile phone networks and local wireless networks. WiFi and Bluetooth are commonly used for the local wireless part of the system. Simply possessing a UMA capable phone does not mean that a subscriber can make use of UMA services since the system requires back-end support from the carrier. UMA is particularly useful in remote areas where mobile phone coverage is poor, as well as inside of buildings where the network signal might not be able to penetrate building walls. In the US, T-Mobile was the first carrier to start offering UMA services. UMA has been officially ratified by the 3GPP and has been renamed GAN, or Generic Access Network, though most often the technology is still referred to by the UMA name.

Focal Length

The focal length of a lens determines how much magnification it provides. A lens with a shorter focal length will be able to "see" a wider view of a subject than can a lens with a longer focal length, which would see a narrower view of the scene, but at a higher level of magnification. Whether a lens seems to be a wide angle or telephoto lens depends on the size of the image sensor it is used with. As a result, one can not say that a given 15mm lens is wide, or that a 200mm lens is telephoto in nature since the size of the image sensor is not known. When speaking of lenses used on 35mm film systems, 35mm of focal length or less is typically considered wide, and 80mm or longer is generally considered telephoto. Digital cameras often refer to their lenses as being "equivalent" to a particular 35mm film camera lens in focal length to give people an idea as to how wide or telephoto it acts when paired with that particular camera's sensor.