The ‘fourth generation’ of mobile communications is known simply as 4G, and it’s how most mobile internet is delivered. It’s what lets you use a mobile phone, dongle, or Mi-Fi device to go online. The previous generation is 3G, which gives you slower speeds but is available far more widely. See also: Mobile broadband.


ADSL, or ‘asymmetric digital subscriber line’, is the standard kind of broadband. It’s delivered through the same copper phone line that connects your home phone. It’s quite a bit slower than fibre optic broadband – average download speeds are usually around 10 or 11Mb, compared to anything up to 362Mb with fibre – but that’s more than enough for a lot of households.


The word ‘broadband’ describes a home internet service you never have to switch off. With broadband, you get much faster speeds than old-fashioned dial-up. You can even use it when someone’s on the phone, unlike dial-up. These days, broadband is the standard form of internet connection, and you can get it just about anywhere – though your choice of providers and speeds depends on where you live. (That’s why we ask for your postcode when you compare broadband with us.)

Cable broadband

Some broadband providers have their own network of lines, in which the wiring between your local exchange and your home is a coaxial cable – rather than a copper phone line or a fibre optic one. A good example of this is Virgin Media. The great thing about coaxial cables is that, unlike copper lines, they don’t lose speed over distance. So with cable broadband you’re almost guaranteed fast download speeds.


You’d be forgiven for thinking it’s something you can eat, but there’s nothing tasty about a ‘cookie’ when you’re speaking broadband. A cookie is a small file that’s sent to your computer to store information about the websites you visit. For example, a cookie can store an online password so you won’t need to enter it each time you use a particular site. As a general rule, cookies are harmless – but for some people they do raise concerns about online privacy. It’s possible to turn cookies off, but some sites may stop working if you do.



If you were using the internet pre-millennium, you’ll remember the not-so-delicate sound of a 56k modem doing its thing. Before broadband, you had to connect to the internet via dial-up – a noisy process taking around 30 seconds – each time you wanted to surf the web. Dial-up was also a lot slower, to the point that images might take several minutes to load, and your phone line would ring engaged if someone tried calling while you were online.

Download limit

Unless you have unlimited broadband, your download limit – also known as a usage limit – is a monthly allowance restricting how much you can do online. Confusingly, it’s not just downloads that count towards your download limit – even checking emails and browsing the web will nibble away at your allowance. The big one to watch though is streaming, especially films and TV in high definition (HD), as a 10GB download limit won’t go far if you regularly watch video online. If you go over your monthly allowance, your provider may charge you extra to keep using the internet until the end of the month.

Download speed

Your download speed refers to how fast data from the internet reaches your home. It’s measured in Mb, or megabits per second, and has a big effect on how you use your internet. Faster download speeds mean that files download quicker, videos buffer in seconds, and web pages load lickety-split. See also: Upload speed.


A telephone exchange is where all the broadband and phone connections of your local area meet and connect to their respective provider’s network. The important thing to note about exchanges when shopping for broadband is that your distance from the nearest exchange can sometimes have an impact on the speeds you’re able to receive – read more about this here.

Fair use policy / Acceptable use policy

Some broadband packages, even unlimited ones, have a ‘fair usage‘ policy attached – rules that say how much data you can download before the provider penalises you. A penalty could come in the form of an extra fee or slower speeds. Luckily, these days a lot of packages are ‘truly unlimited‘ with no limits whatsoever. However, most do have an ‘acceptable use‘ policy. This usually means that by signing up, you promise to use your broadband connection reasonably – in other words, you’re a normal domestic household and won’t be doing anything illegal online.

Fibre optic

Fibre optic broadband is literally delivered through fibre optic cables – yes, like the ones in those cool lamps. They allow data to be transferred at a much, much faster rate than traditional copper cables, so a home broadband connection with a fibre optic line will get nice fast speeds. The main fibre optic network in the UK is owned and maintained by BT, with average download speed of packages as high as 67Mb.

Fibre cables


The ‘FTT’ in acronyms like FTTC stands for ‘fibre to theā€¦‘ – and, as you can guess, they refer to fibre optic broadband. In particular, they refer to how far the fibre optic line stretches before it’s replaced by a copper one. Most home broadband is FTTC (fibre to the cabinet), meaning the line is fibre from the exchange to your local street cabinet. Some providers offer FTTP (fibre to the premises), in which the line is fibre all the way from the exchange to your home. You may also see FTTH (fibre to the home), and FTTB (fibre to the building, business, or even boat).

Gigabytes (GB)

1GB (one gigabyte) is 1000MB (one thousand megabytes). See Megabyte (MB) below.

IP address

An IP address, or internet protocol address, is a number assigned to your computer or device when it goes online, so that the network knows where to send data to. It works just like a postal address, except it sends web data rather than letters. An example of an IP address is See also: Static IP address.

Line rental

You’ll need to subscribe to line rental if you want a home phone connection and, usually, broadband – in fact, line rental is generally included in a broadband package. It makes your phone line active, and able to send and receive calls or data. Read more about line rental here.

Local loop unbundling (LLU)

Exciting as it sounds, a ‘local loop‘ is really just a big bunch of wires. Specifically, it’s the big bunch of wires that links your house to the local telephone exchange. BT looks after our national telecoms infrastructure through its separate Openreach network. Openreach lets LLU providers, like TalkTalk and Sky, install their own equipment inside the exchange and serve their customers directly, rather than simply re-selling a wholesale BT internet service.

MAC (code)

To switch broadband, you used to have to contact your current provider for a ‘migration authorisation code’, which you’d then give to your new provider. However, Ofcom has updated its rules, and you’re no longer required to do this – your new provider will completely take care of the switch for you.

Megabit (Mb)

A ‘megabit’ (not to be confused with a megabyte) is a unit of measurement for the transfer of digital information or data, which to most of us just means broadband speeds. For example, a BT Superfast Fibre broadband package with average download speeds of 50Mb is, at least in theory, capable of transferring 50 megabits of data per second. However, actual speeds can vary depending on a wide range of factors – like how far you are from the local exchange, the wiring in your house, your router, and so on.

Megabyte (MB)

A ‘megabyte’ (not to be confused with a megabit) is a unit of measurement for digital information or data. Megabytes refer to the amount of data that a file takes up. Whenever you download something, like a file or a video or a web page, it takes up a certain number of megabytes. A song from iTunes may take up 5MB, for instance. That can contribute to your download limit, if your broadband package or mobile plan has one, though these are usually measured in gigabytes (GB).

Mobile broadband

Broadband which is delivered through 4G or 3G is known as mobile broadband. It’s how you get the internet on your mobile phone, cellular-enabled tablet, dongle, or Mi-Fi device. See also: Wireless broadband.


Ofcom is that all-important regulatory body, who makes sure that all is up to speed in the world of telecoms, broadband, television, and phones in the UK – and in particular, making sure that customers get the good services they deserve. As part of this, Ofcom conducts a rigorous audit of broadband, home phone and TV comparison sites to ensure information is clearly presented, impartial and accurate at all times. Our website is one of only a small handful given the Ofcom seal of approval.


Some telecoms companies offer only one service, such as home phone. Others offer two, or three. Others, however, offer four: broadband, home phone, TV, and mobile services. These are known as ‘quad-play’ providers, and include Virgin Media, BT, and TalkTalk.


Depending on how romantic you feel, your router is either the throbbing heart of a modern, wirelessly connected home, or a plastic box of wires with flashing lights. It’s a standard piece of kit that comes with most UK broadband packages, and is necessary for connecting all your devices to the internet. Your router is hooked up to the broadband connection and pumps out a Wi-Fi signal that’s picked up by any device you use to access the internet at home.

Static IP address

An IP address (see above) is a number that identifies your device so that data can be transferred to it. Usually these are dynamic, meaning they can change, but you can also get static IPs – which don’t change. They’re essential for things like accessing your computer remotely, hosting a server, or running CCTV, and you’ll usually find them included in business broadband packages.


Forget surfing the net, that’s so late 90s. These days it’s all about streaming – watching TV, movies, and video clips, or listening to music, radio, and podcasts, over the internet. Streaming, as opposed to downloading, means that files aren’t stored on your computer and you won’t need to wait for the whole thing to download before you’re allowed to start playing it. Be careful, though – streaming video, particularly in high definition (HD), will eat up your data allowance really quick

Listening to music on a laptop


A lot of modern 4G-connected smartphones have a feature that lets you turn them into a Wi-Fi hotspot. It lets other gadgets connect to your phone and use the internet through it – the same way you connect them to a home router. This is known as tethering. Bear in mind that tethering will still contribute to your data usage, and a lot of mobile networks put limits on tethering.

Traffic management

If lots of people use the internet at the same time, the broadband network can get congested and speeds drop. To combat this, many providers manage web traffic – slow certain types of online activity and prioritise others – to ensure everyone gets a consistent performance. Traffic management is also often used to restrict or ‘throttle’ speeds if you exceed your monthly download limit or download excessive amounts. Only a few providers manage web traffic these days.

Upload speed

If your download speed (see above) refers to how fast data is transferred to your device, your upload speed is how fast data is transferred from your device. Your upload speed affects how long it takes to post pictures to social media, how reliable your Skype calls are, and how easily you can send emails. Again, it’s measured in Mb or megabits per second, and is usually a far lower number than your download speed.


There are two ways to connect a device to a router: either directly using an internet cable, or wirelessly using Wi-Fi. Your router sends out a signal through an antenna, and your gadgets then connect to that. You’ll find Wi-Fi on almost all home routers, as well as via hotspots in cafes, hotels, universities, and various public places.

Wireless broadband

Any broadband that isn’t delivered through a fixed line, but instead through signals in the air, is known as wireless broadband. It could be mobile broadband or satellite broadband, for instance. The word ‘wireless’ is also often used to refer to Wi-Fi (see above).