A 3.5mm Jack is a common type of audio connector used for connecting stereo headphones into digital devices such as a portable music player, mp3 player and mobile phone.

3G stands for 3rd-generation. Analogue mobile phones were the first generation and digital mobile phones marked the second generation.

3G is loosely defined, but generally means high broadband like data speeds, always-on data access, and greater voice capacity.

With a 3G mobile phone you can access the Internet at high speed, make and receive video calls and watch live streaming videos on your mobile phone.

Internal
The aerial of the mobile phone is contained inside the body of the device, an internal aerial is also known as an intenna.

External
The aerial of the mobile phone is contained outside the body of the device. Many of the 1st and 2nd generation mobile phones had an external aerial; nowadays most mobiles have an internal aerial.

The aperture is the hole or opening of the camera lens through which light is admitted.

The aperture of a camera lens can usually be adjusted to control the amount of light reaching the film or image sensor. In combination with variation of shutter speed, the aperture size will regulate the film's degree of exposure to light. Typically, a fast shutter speed will require a larger aperture to ensure sufficient light exposure, and a slow shutter speed will require a smaller aperture to avoid excessive exposure.

In general, the smaller the aperture (the larger the number), the greater the distance from the plane of focus the subject may be while still appearing in focus.

The lens aperture is usually specified as an f-number, the ratio of focal length to effective aperture diameter. A lens typically has a set of marked "f-stops" that the f-number can be set to. A lower f-number denotes a greater aperture opening which allows more light to reach the film or image sensor.

There are a numerous types of audio formats that a mobile phone can be compatible with including:
• AAC
• AAC+
• AAC LC
• AAC LTP
• AMP
• AMR
• AMR-NB
• AMR-wB
• eAAC
• eAAC+
• MIDI
• Mono
• M4A
• MP2
• MP3
• MP4
• MPEG4
• Real
• Real Audio
• WAV
• WMA

Battery Capacity is measured is milli-amps per hour (mAH).

An milli-ampere (milli-amp) is a unit for measuring the amount of electricity flowing through a circuit. One thousand milli-amps per hour is equal to a current of one thousand milli-amps flowing for one hour, Two thousand milli-amps per hour is equal to a current of two thousand milli-amps per hour.

Therefore, the larger the mAH of the battery the greater the electrical capacity.

Lithium Ion (Li-Ion)
A relatively modern battery offering a very high charge density, storing a lot of energy. Used in many portable electronic devices including digital cameras, laptops, mp3 players as well as mobile phones.

Lithium Polymer (Li-Polymer)
Similar to the Li-Ion battery but with slightly less charge density. Can be produced to be ultra-thin (1mm) and often used in many PDA’s and smart phones.

Nickel Cadmium (NiCd)
Superseded by the Lithium Ion battery the Nickel Cadmium battery was used in many domestic appliances. The low energy density charge compared to the Lithium Ion has meant it is no longer suited to many of today’s mobile phones.

Nickel Metal Hydride (NiMH)
Similar to the NiCd battery but with a greater charge density. The NiMH battery has also now been superseded by the Lithium Ion battery, which has a greater charge density.

Bluetooth is wireless radio technology protocol for sending audio and video data between mobile devices - laptops, notebooks, Handheld Computers, PDA's and other Bluetooth enabled devices including mobile phones and headsets.

The first generation of Bluetooth permits exchange of data up to a rate of 1 Mbps per second over a range of around 10 meters. A single Bluetooth-enabled device is capable of making phone calls, synchronising data with desktop computers, sending and receiving faxes, and printing documents all without the need for wires.

A dedicated key or button on the mobile phone for instant activation of the digital camera. Enables you to take photographs with the mobile phone as if it was a digital camera.

Typically measured in mega-pixels camera resolution can be calculated by multiplying pixel columns by pixel rows and then dividing by one million

The greater the camera resolution, i.e the higher the mega-pixels of the camera the better the picture quality will be.

Any camera that has a resolution of at least 1 megapixel is of good quality.

Digital zoom is a method of decreasing (narrowing) the angle of view of a digital photographic or video image. Digital zoom is accomplished by cropping an image down to a centered area with the same aspect ratio as the original, and usually also interpolating the result back up to the pixel dimensions of the original. It is accomplished electronically, without any adjustment of the camera's optics, and no optical resolution is gained in the process.

The greater the digital zoom the more you can focus in on a particular image or photograph area, although the quality of the image is often lost the further you zoom.

CSTN
Colour Super Twisted Nematic (CSTN) is a type of LCD display technology. The technology is known as passive-matrix, meaning that each pixel on the display must be refreshed individually many times each second. This results in low response times and limits the brightness and contrast of the display.

LCD
Liquid Crystal Display (LCD) is the most popular type of display featured on mobiles. LCD displays have low energy requirements and offer sharp quality. There are a number of different types of LCD technology including CSTN and TFT.

TFT
Thin Film Transistor (TFT) is a type of LCD display technology. TFT offers excellent image quality and response time, but uses more power and is generally more expensive than CSTN.

VGA
Video Graphics Array (VGA) is a standard resolution size for images and displays. VGA is 640 pixels wide by 480 pixels tall.

QVGA
Quarter-VGA (QVGA) is a standard resolution size for high resolution images and displays. QVGA is one-quarter the area of VGA.

Enhanced Data for Global Evolution (EDGE) is an upgrade technology for GSM mobile networks that triples data speeds over GPRS.

EDGE is used automatically when supported by both the mobile network and the mobile device. When EDGE is not available, GPRS will be used resulting in a slower data speed.

Capabilities of EDGE technology is 236 Kbps, although most speeds will average at around 135 Kbps due to network restrictions. GPRS when operating over EDGE is known as EGPRS.

SMTP
Simple Mail Transfer Protocol (SMTP) is a popular Internet protocol for sending and receiving email messages. Emails using SMTP can be sent between mobile phones and computers. Common SMTP email services include Hotmail and Yahoo! Mail.

IMAP4
Internet Message Access Protocol (IMAP) is an Internet protocol used to download emails from an email server to an email client. An updated version of POP, IMAP offers more intelligent handling of emails from multiple devices.

POP3
Post Office Protocol (POP) is an Internet protocol used to download emails from an email server to an email client. POP3 is the most common email downloading protocol. Using POP3 you can download emails from a Hotmail or Yahoo! Mail account to your mobile phone.

APOP
Authenticated Post Office Protocol (APOP) is similar to POP3, with the use of added encryption of your username and password login details between your email client and your mail server.

Enhanced Messaging Service (EMS) is a half-way messaging service, more advanced than SMS (text messaging) but less advanced than MMS (picture messaging).

It allows you to send text messages and include small animations, ringtones and wallpapers to other mobiles as well as sending text messages longer than 160 characters.

Exposure is the total amount of light allowed to fall on the photographic medium (photographic film or image sensor) during the process of taking a photograph. Exposure is measured in lux seconds, and can be computed from exposure value (EV) and scene luminance.

Exposure time is controlled in a camera by shutter speed and the illumination level by the lens aperture. Slower (longer) shutter speeds and greater (bigger) lens apertures produce greater exposures.

Shutters types on mobile phones can be either:
• Automatic
• Rolling

The amount of memory contained on a storage or memory card that a phone can handle.

External memory is often measured in mega-bytes (MB) or giga-bytes (GB). One GB (1GB) of data is equal to One Thousand MB’s 1,000MB) of data.

Therefore the greater the MB or GB of the mobile phone the more memory it has to store more data; pictures, messages, video files, music files and software applications.

FM Radio is a popular broadcast medium for transmitting sound over the air.

Mobile Phones with an integrated FM Radio can tune into all radio stations that transmit on the FM frequency band, including BBC Radio 1 and 2 and many independent commercial stations.

The focus length determines the angle of view, and the size of the image relative to that of the object; the maximum aperture limits the brightness of the image and the fastest shutter speed usable.

Focal lengths are usually specified in millimeters (mm) or centimeters (cm). The greater the focus length of a digital camera the greater the detail of the photograph that can be taken.

Focus range is usually specified in millimeters (mm) or centimeters (cm). The greater the focus range of a digital camera the greater the detail of the photograph that can be taken.

Mobile phones are designed in a number of different styles (known as forms). There are several common types of mobile phone forms.

Candybar
Also known as “Bar” or “Block”, the Candybar form is the most basic and common style of mobile phone. The handset is designed as one solid block with no moving body parts. To prevent numbers being accidentally dialled when in a pocket, a number lock is used requiring a combination of keys to be pressed to “unlock” and activate the phone.

Clamshell
Also known as “Clam” or “Folder”, the Clamshell form consists of two parts connected by a hinge. The mobile phone folds closed when not in use. The top part of the phone usually contains the main display screen and the speaker with the bottom part containing the keypad and battery.

Monoblock
A Monoblock form is an alternative name for the Candybar form, usually used when mentioning a mobile targeted at the business customer.

Monolith
A Monolith form is an alternative name for the Candybar form, usually used when mentioning a mobile phone with no visible screen or keypad.

PDA
A PDA form usually consists of one or two parts containing a large screen with a full QWERTY keyboard. PDA forms can usually be operated using a stylus with the touch screen.

Slide
Also known as a “Slider”, the Slide form consists of two parts that use a sliding hinge. The mobile phone can be slid open to make and receive a call. The top parts of the phone usually contain the main display screen with the bottom part containing the keypad and battery.

Swivel
Similar in appearance to the Candybar form, Swivel mobile phones usually contain two parts that can be swivelled for another purpose such as changing the mobile phone into a word processor or email device.

Twist
Similar in appearance to the Candybar form, Twist mobile phones usually come in a block with one part that can be twisted for another purpose such as changing the mobile phone into a video recorder and digital camera.

Frequency bands are the radio spectrum frequencies for the operation of the GSM system for mobile phones. There are 4 main frequency bands used in mobile communication.

850 MHz (GSM-850)
Used in most parts of the United States, Canada and South America GSM-850 uses the frequency range 824 – 849 MHz to send information from the Mobile Station to the Base Transceiver Station (uplink) and the frequency range 869 – 894 MHz for the opposite direction (downlink).

900 MHz (GSM-900)
Used in most parts of the world GSM-900 uses the frequency range 890 – 915 MHz to send information from the Mobile Station to the Base Transceiver Station (uplink) and the frequency range 935 – 960 MHz for the opposite direction (downlink).

1800 MHz (GSM-1800)
Used in most parts of the world GSM-1800 uses the frequency range 1710 – 1785 MHz to send information from the Mobile Station to the Base Transceiver Station (uplink) and the frequency range 1805 – 1880 MHz for the opposite direction (downlink).

1900 MHz (GSM-1900)
Used in most parts of the United States, Canada and South America GSM-1900 uses the frequency range 1850 – 1910 MHz to send information from the Mobile Station to the Base Transceiver Station (uplink) and the frequency range 1930 – 1990 MHz for the opposite direction (downlink).

Dual Band
The ability for the mobile phone to operate on two different frequency bands either 800 MHz or 1900 MHz. The phone can be used in countries whose networks use these frequency bands. Includes all countries in Europe, Asia and Africa.

Tri Band
The ability for the mobile phone to operate on three different frequency bands either 800 MHz, 1800 MHz or 1900 MHz. The phone can be used in countries whose networks use these frequency bands. Includes all countries in Europe, Asia and Africa, Australasia and some areas of the USA.

Quad Band
The ability for the mobile phone to operate on four different frequency bands either 800 MHz, 850 MHz, 1800 MHz or 1900 MHz. The phone can be used in countries whose networks use these frequency bands. Includes all countries in Europe, Asia and Africa, Australasia and most of the USA.

General Packet Radio Service (GPRS) is a wireless data transmission service based on packet transmission, which is similar to the way Internet email is delivered.

GPRS is being absorbed in 3G but is widely regarded as a 2.5G technology. It is compatible with GSM and TDMA networks and offers data speeds in the 115 kbps range.

GPRS allows you to connect to the Internet using your mobile phone with the ability to download games, music and videos. New technologies including EDGE and 3G offer much quicker speeds for mobile Internet connection than GPRS.

High Speed Circuit Switched Data (HSCSD) is an alternative to GPRS technology allowing high speed data transmission on the GSM mobile network.