TECHNOLOGY :: Definitions

Please note that these definitions are aimed specifically at non-technical people and as such are somewhat simplified.

ADSL - Asynchronous Digital Subscriber Line. The technology used to provide broadband connections to businesses and homes over standard copper telephone lines. Asynchronous comes from the fact that the download speed is considerably faster than the upload speed.

Bandwidth - This term is widely but incorrectly used to mean data rate, or data transmission rate.

Broadband - An internet connection type that has a much higher data rate than conventional dial-up or ISDN connections. A data rate of 256kbps or greater would be considered broadband and can be delivered by ADSL, Cable Modem or Satellite.

Data Rate - ("data transfer rate", "transmission rate") The amount of computer information that can be transferred per second by a communications channel (computer network or internet connection) or a computing or storage device. Example data rates: 56k Modem, theoretical maximum transfer rate of 56,000 bits of data per second, roughly equivalent to 6kb per second. A standard ADSL 512kbps broadband connection transmits roughly 60kb per second of data.

Download - To retrieve data from a website, the data flows from the internet to you

Latency - The period of time that a piece of information is held by a computer network device before it is forwarded. A good example would be a modem, the latency is the time it takes for the data to be processed by the modem before it actually starts being transmitted across the telephone wire. This time is the result of a process being applied to the data, in the case of the modem, the time to compress it and convert to an analogue signal from the original digital signal. A very low latency is important for good transmission of data. Satellite broadband 'modems' suffer from high latency, whereas good ADSL 'modems' have low latency. High latency will adversely affect web browsing, voice over internet and VPN connections, even if data transmission rate is large.

Upload - To send data to the internet, e.g. when sending an email this is uploading.