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Broadband Glossary

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Don't know your 'bit' from your 'bundle' or your 'downstream' from your 'download'? Then read our glossary of key terms to help you burst through that broadband jargon and get the most out of your broadband internet service provider.

If you are struggling to understand a broadband deal or contract, then you are not alone. Broadband firms often seem unable or unwilling to write in plain English, causing confusion among their customers.

Technical terms can also be off putting. So to make sense of the jargon, MoneySuperMarket has compiled a glossary of some of the most commonly used broadband terms.

3G broadband

Most of us access the internet on our mobiles and laptops using third generation – 3G – mobile technology. It was introduced to the UK in 2003 and now covers most of the country.

4G broadband

Fourth generation mobile technology – 4G – promises more reliable connections and faster download speeds. Coverage is still patchy but it will eventually replace 3G mobile broadband.


If you want the full version, it’s ‘asymmetric digital subscriber line’.

Basically, ADSL allows data to be transferred quickly over the copper wires of your existing phone line and is a common internet connection. Your broadband provider puts a ‘splitter’ into your telephone wall socket so that you can run both your telephone and your broadband connection simultaneously.

In other words, you can chat on the phone while surfing the net.

Nearly every home in the UK can get an ADSL connection, with speeds of up to 8 Mbps. But the further you live from the telephone exchange, the slower the likely connection speed.


A jazzier version of ADSL that uses the same copper wires but more up-to-date technology. It’s quicker than ADSL with speeds of up to 20 Mbps. It is also now widely available throughout the UK.


Most of us are inundated with unwanted emails, or ‘spam’, but anti-spam software can help to filter out the junk.

Some internet service providers offer free anti-spam software with their broadband packages. Your anti-virus protection might also get rid of unwanted spam. Remember that you don’t need anti-spam software if you use webmail, such as Google Mail or Hotmail, as it’s already built in.


Spyware is a malicious program that steals your personal information without your knowledge or consent. It can also slow down your computer and even alter your programs and settings.

Some internet service providers include anti-spyware in their broadband packages, or it might come as part of an anti-virus program.


Anti-virus software can detect, prevent and remove malicious software, or ‘malware’, such as viruses and ‘trojans’.

Malware is the curse of modern technology and can damage your computer or intercept personal information, so some sort of protection is essential.

Many service providers include free anti-virus software with their broadband deals, or you can download free software from the internet. If you pay for protection, you normally get additional features, but they are not always compatible with older computers that have limited capacity.


The term ‘bandwidth’ can be confusing because it can be used to describe two different things.

Some broadband firms use bandwidth to mean the data transmission speed. In other words, the speed at which you can upload and download information online.

To others, it refers to the amount of data you can download. For example,your package might include a bandwidth of 6GB.

Bandwidth contention ratio

The bandwidth contention ratio is the maximum number of people who will share your broadband connection. So, if the ratio is 50:1, you could share your connection with a maximum of 49 other people at any one time.

The higher the contention ratio, the lower the potential download speed.


Broadband bonding is a way to speed up your broadband connection by ‘bonding’ several telephone lines together. It gives you greater bandwidth and therefore faster speeds.


There are two definitions of the term ‘capping’.

It is commonly used to describe a download limit. So, you might be able to download only a certain amount of data each month under the terms of your contract.

If you breach the limit, you usually have to pay a penalty charge.

Capping can also refer to a cap on the broadband speed, either as a punishment for downloading too much data, or as a way to manage internet traffic during peak periods.


The digital subscriber line (DSL) is the generic name for digital, rather than copper, telephone lines that carry data at high speeds. These lines are made of glass or plastic fibres.


A ‘digital subscriber line access multiplexer’ is a device in the telephone exchange that enables telephone lines to make faster connections to the internet.


Dial-up is a way to access the internet through the telephone line. It is slower than broadband and means you cannot use the internet and the telephone at the same time. Dial-up has mostly been replaced by broadband.


The process of transferring data (such as a video or music track) for storage on your computer. This is opposed to ‘streaming’, where you watch or listen on your computer screen without actually transferring the item to your computer itself.

Download limit 

Your broadband package will often have a download limit, which caps the amount of data you can download from the internet over a specific time period, usually a month. It is also known as a bandwidth cap and is usually expressed in MB or GB.

Download speed 

The download speed is the speed at which you can download data from the internet to your computer.

Fair usage policy 

Many broadband firms offer ‘unlimited’ broadband deals that allow you to download as much data as you like. But unlimited rarely means unlimited – most internet service providers operate a ‘fair usage’ policy, which means if you download an unusually large amount of data, you could incur a penalty.

Fibre-optic broadband

Copper telephone cables weren’t built with the internet in mind, so they can be slow. Fibre-optic cable, as used by Virgin and BT Infinity, is quicker and will eventually replace all the older copper cable.


A firewall restricts unwanted or undesirable data traveling from the internet to your computer. It is often included in your broadband deal and should be used in conjunction with anti-spyware and anti-virus protection.


If you have fixed-line broadband, you hook up to the internet either through a fibre-optic cable, or an ADSL connection. Fixed-line broadband is distinct from mobile broadband, which connects to the internet using a mobile signal.


A gigabit (Gb) is a unit used to measure the speed at which data travels across an internet connection, sometimes written as Gbps, or gigabits per second. There are 1,024 megabits in one Gigabit or Gb.


A gigabyte (GB) is a unit used to measure the size of a data file. There are 1,024 bytes in a kilobyte (KB), 1,024 kilobytes in a megabyte (MB), and 1,024 megabytes in a gigabyte.


A hotspot is somewhere you can wirelessly connect to the internet using a local area network. You might need a security password. Some hotspots, such as cafes, also charge a fee.

IP address 

IP stands for internet protocol and is the unique code that identifies every computer that is connected to the internet. It is similar to a house or telephone number.


Internet protocol television allows you to watch TV through your broadband connection. It offers programmes on demand and you can fast-forward, rewind, stop and pause any shows you watch. If you want to watch IPTV through a standard TV, you will need a set top box.


An integrated services digital network, or ISDN, combines voice, data and video into a single cable for fast communication.


Your internet service provider (ISP) is the company responsible for your internet connection – so the company that sends your broadband bill.


Local loop unbundling allows other ISPs to use BT telephone exchanges, often to upgrade an ADSL connection to ADSL2+.


Your landline is your home or office telephone line. If you don’t have a landline, you will probably have to opt for mobile broadband.


If you want to switch to a different ISP you will usually need a Migration Authorisation Code (MAC). Your existing provider must supply the MAC free of charge within five working days, but it is valid only for 30 days.

MACs can be cumbersome and complicated. But a new system is set to do away with the codes altogether by the end of 2014, hopefully making switching simpler.


A megabit or Mb measures internet speed and is often expressed as Mbps or megabits per second. There are 1,024 kilobits in one megabit and 1,024 Mb in a gigabit. You can find out more in our guide to bits and bytes.


Data files are often measured in megabytes (MB). So, a file might be 16 megabytes.

Mobile broadband 

Mobile broadband allows you to access the internet on the move through a mobile phone or other portable device using the mobile network.


A modem is the essential piece of kit that connects your computer to the ISP so you can access the internet.


A router enables more than one computer to connect to the same network. You then connect the router to the modem, so that all the computers can access the internet.

A wireless router works on the same principle, but allows a wireless gadgets, such as Smartphones or iPads, to hook up to your home internet connection. Modems and routers are sometimes combined into one, hybrid device.


If you watch videos or listen to music over the internet without first downloading it onto your computer, you are ‘streaming’.


Your ISP might deliberately slow down or ‘throttle’ your internet connection if you breach your download limit, or if there is unusually heavy traffic.

Unlimited broadband 

There is no limit on the amount of data you can upload and download with an unlimited broadband contract. However, most contracts are subject to a fair usage policy – see above.


The opposite of downloading, uploading is when you send information from your computer to the internet. For example, when you send an email or a photo to a website. It is sometimes referred to as upstreaming.

Usage allowance 

Many broadband packages come with a monthly usage allowance, which sets out the amount of data you can upload or download in any one month. It is typically given in GB.


Video on demand enables viewers to download or stream video content whenever they choose.


Voice over internet protocol allows you to talk online, in much the same way as you would over the phone, using a broadband connection. Skype is probably the most well known VoIP system, combining video and audio.


Webmail services store emails online, instead of downloading them to your computer. The most common webmail services in the UK are Hotmail, Yahoo! and Gmail, but there are many others, and most of them free.


The term Wi-Fi is commonly used to refer to devices that work wirelessly over a Wi-Fi network, or more accurately a wireless local area network (WLAN).

Wi-Fi is now widely available in public places such as cafes, airports and hotels. You can also install a wireless router in your home or office so that you don’t have to run separate wires to different computers.

Wireless broadband 

Any internet connection can be wireless. You just need a computer with the right technology and the right router or modem.

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