What is Wi-Fi and how does it work?

In this guide

You’ll be familiar with its yin-yang logo from the ubiquitous stickers advertising public internet access in pubs, hotels and coffee shops across the UK. But what actually is Wi-Fi?

In this guide we’ll explain what Wi-Fi networking is, how it works, and how you can use Wi-Fi at home and on the move to get connected without cables.

What is Wi-Fi?

Wi-Fi is a wireless networking technology that allows devices like computers, tablets, games consoles and smartphones to communicate without a physical link. 

Rather than being tethered with a cable you can simply connect over the air, providing an easy way to network homes and access broadband internet without cables cluttering up the place.

What does ‘Wi-Fi’ mean?

The term Wi-Fi is not short for anything. Though inspired by the audio term ‘Hi-Fi’ it does not stand for ‘Wireless Fidelity’.

The name and logo were created for marketing purposes. It’s a trademarked name owned by the Wi-Fi Alliance, an organisation which certifies wireless networking equipment and promotes the use of the technology.

Wi-Fi is the official name, though it is commonly (and incorrectly) spelt ‘WiFi’.

Often you’ll see wireless-capable equipment boast that it has been certified by the Wi-Fi Alliance. This means it meets the particular standards for their certification process, and it can be an indication a device offers a good level of security or compatibility, but not all Wi-Fi hardware has been certified. Typically this is due to the cost of the certification process and not a sign that it’s incompatible with other Wi-Fi gear, so don't worry too much if you've got something missing the certification mark.

How does Wi-Fi work?

Wi-Fi transmits data using radio waves, mostly in the 2.4GHz-5GHz frequency range. This allows devices to communicate wirelessly and means you don’t need network cables, so it’s very easy to create a home network without having to worry about routing wires.

The range of a Wi-Fi network depends on the frequency, transmission power, and environment. Using standard consumer and business Wi-Fi devices you can expect an indoor range of around 150ft for a 2.4GHz network, going up to around 300ft outdoors. But it is possible to get a much longer range using directional antennas and more powerful transmitters.

Wi-Fi frequencies and speeds - what is 802.11? 

Something you’ll come across when looking at Wi-Fi hardware are the 802.11 specifications, and they need some explanation because it’s important to understand what they mean to get the most out of Wi-Fi. 

These Wi-Fi standards are created by the Institute of Electrical and Electronics Engineers (IEEE), and although the precise technical details aren’t something most of us need to know, they do provide a quick reference to the speed of a wireless network. In short, the newer the 802.11 standard a Wi-Fi device supports, the faster it will be. That's the theory, anyway!

The table below shows the top speeds of the most common Wi-Fi specifications. These are backwards compatible, so you can buy a cutting edge 802.11ax router and still connect old hardware (though frequency also needs to be considered - see below). Keep in mind that these are theoretical maximums, particularly when it comes to 802.11ac and 802.11ax - they have very high top speeds in ideal conditions but in reality the actual speed will be much lower (though still better than the older standards). You can also get better speeds using technology such as beamforming and MIMO.

802.11 standard

Wi-Fi version no.

Max speed

Frequency

802.11b Wi-Fi 1 11Mb 2.4GHz
802.11a Wi-Fi 2 54Mb 5GHz
802.11g Wi-Fi 3 54Mb 2.4GHz
802.11n Wi-Fi 4 300Mb (5GHz) 2.4 / 5GHz
802.11ac Wi-Fi 5 7Gb 5GHz
802.11ax Wi-Fi 6 10GBb 2.4GHz & 5GHz

Also included in the table are the new Wi-Fi version numbers. These have been recently introduced as a friendlier alternative to the 802.11 labels, though as it’s a new initiative there will be lots of devices sticking to the old naming convention so it still helps to know what each of the IEEE numbers mean.

The table also shows Wi-Fi network frequencies. Many devices only utilise the 2.4GHz band, which provides greater range and penetration of obstacles like the walls of your home, but is more prone to interference as it’s the same frequency used for cordless telephones and other devices. The 5GHz band (supported by newer 802.11n, ac, and ax routers, as well as the old 802.11a) can be much faster but also have a shorter range.

When buying Wi-Fi hardware you should check that the supported frequencies match your existing Wi-Fi setup, though to simplify things we’d recommend always going for ‘dual band’ equipment as it will then support both 2.4GHz and 5GHz. Not only is this better from a compatibility point of view but it also means you can switch to using 2.4GHz if the limited range of 5GHz proves to be a problem.

How to setup Wi-Fi

Setting up Wi-Fi at home is straightforward. To do it you just need a Wi-Fi router, which is the key bit of hardware which generates a wireless network. Your broadband provider will usually supply one for free, or you can purchase your own

In brief, here are the steps to setting up Wi-Fi for the first time with a new router: 

  1. Plug in your Wi-Fi router. If you’re not using wired networking too then the only cables required are the power and broadband connection.
  2. Wait for the Wi-Fi network to come online. This can take a couple of minutes, and will be indicated by a light on the router.
  3. Using a Wi-Fi compatible device (such as a laptop or smartphone) scan for the Wi-Fi network. The default network name will be shown in the router manual or on a sticker attached to the router.
  4. Select the Wi-Fi network and enter the password supplied with the router.

You should now be connected to Wi-Fi!

Which broadband provider has the best free Wi-Fi router?

The quality of ISP supplied routers is variable. Some will update their kit regularly, others may go years without changing the hardware and can be a little outdated by modern standards. 

Among the big ISPs, the BT Smart Hub and Virgin Media Hub stand out as the best freebies. Both support fast 802.11ac Wi-Fi and gigabit wired networking, and have multiple antennas for dual band support and better signal strength.

To find out more about what kind of router each provider uses you can read more about them in our provider reviews section.

Wi-Fi router security and customisation

After you’ve set it up for the first time and confirmed everything works there are some additional changes you can make by accessing the router’s administration panel. Instructions for this will be given in the user manual, but generally it’s achieved by using a web browser to connect to the router with an IP address - for example https://192.168.0.1

Change the admin password

If your router has a default admin password (which is often simply ‘admin’) then it’s very important to change this to a strong passphrase as a priority. Some routers will not have a password to begin with but will prompt you to create one when logging in for the first time.

Change the network name and password

You can customise the Wi-Fi network name (called an SSID - Service Set Identifier) to anything you like. This is helpful if there are lots of networks in your area with similar names. The Wi-Fi password can also be changed here. 

Set up a guest network

Some routers offer a guest network feature. This is a segment of your Wi-Fi network with its own name and password so visitors can get online without giving away your main Wi-Fi login. It also prevents them from accessing any shared devices (such as hard drives or printers) on your network.

Create a dual band network

If your router uses both 2.4GHz and 5GHz frequencies you can have them running at the same time to get the fastest Wi-Fi speeds while still supporting older devices and benefitting from the coverage of a 2.4GHz network (5GHz is faster, but has a shorter range and the signal is more likely to be blocked by the walls of your home). For ease of use give both networks the same name and let your devices choose the best connection.

For more help with configuring your router read our in-depth guide to changing router settings.

Frequently Asked Questions about Wi-Fi

What devices use Wi-Fi?

Wi-Fi is used by a huge range of devices: smartphones, tablets, games consoles, computers, cameras, smart home gadgets...if it needs internet access then it can probably be connected to Wi-Fi. To find out if a device supports Wi-Fi check the specifications or look for the Wi-Fi symbol.

Can you get Wi-Fi for free?

Free Wi-Fi hotspots can be found all over the world. They’re common in coffee shops, pubs, restaurants and hotels but you may also find them in your local bank or barber. Check out our guide to Wi-Fi hotspots to learn more about free Wi-Fi, and how to find it.

What is a mobile Wi-Fi hotspot?

A Wi-Fi dongle, or mobile hotspot, is a mobile broadband dongle which creates a Wi-Fi network to share its mobile internet connection. This lets you get mobile broadband access on any Wi-Fi device.

What is an access point?

A Wireless Access Point (WAP, or just AP - Access Point) is a device which connects to a wired network in order to provide wireless connectivity to that network in the local area. These are usually used by organisations where it may be necessary to support a very large number of users. At home we can just use a Wi-Fi router, which is a hub that provides both wired and wireless networking and internet access in one device.

How can I improve weak Wi-Fi signal?

For the best coverage your Wi-Fi router should be placed in a central position in your home, away from walls, and anything which could interfere with the signal (such as cordless phones or fridges). Use a 2.4GHz network for the best signal range and penetration. You can use a Wi-Fi signal booster to provide coverage in areas where the Wi-Fi is weak or nonexistent. 

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