What is the difference between 2.4GHz and 5GHz WiFi?

These refer to the radio frequency band your router uses to communicate with your devices. The 2.4GHz band travels farther and passes through walls more easily, but is slower and more crowded (it is shared with microwaves and some cordless phones). The 5GHz band is faster but has shorter range and struggles with walls. Most modern routers broadcast both simultaneously, and devices switch automatically. A third band, 6GHz, is used by WiFi 6E and WiFi 7 routers and offers the fastest speeds with the least interference, though range is shorter still.

Does closing WiFi password protection slow down my internet?

No. Encryption is handled by the router and device hardware at the network layer, before your internet connection is involved. It has no meaningful effect on speed. An open WiFi network is slower only if many people are using it, not because it lacks encryption.

Why does my WiFi slow down when my neighbor is using their WiFi?

WiFi uses shared radio spectrum. All devices and routers in range compete for the same frequencies. In dense housing (apartments), this competition is significant. Your router tries alternative channels, and WiFi 6 includes OFDMA which lets multiple devices share a channel more efficiently, but shared spectrum is a physical limitation with no complete fix.

Is WiFi radiation dangerous?

WiFi uses non-ionizing radiofrequency radiation, the same type as FM radio, cell towers, and baby monitors. It is fundamentally different from ionizing radiation (X-rays, UV). Major health organizations including the WHO and FCC have found no evidence of adverse health effects from typical WiFi exposure levels. WiFi routers emit far less power than a cell phone.

What does a WiFi router actually do?

A WiFi router does two main jobs. First, it routes data between your home network and the internet (that is the router part). Second, it converts data into radio signals that your devices can receive and transmit on (that is the access point part). Most home routers combine both functions, plus a switch (for wired connections) and sometimes a modem. Mesh systems add multiple access points that work together to cover a larger area.

How WiFi Works | distill.md

You use it every day without thinking about it. Your phone connects, your laptop connects, your TV connects. It is there when you need it and maddening when it is not. But most people have no idea what is actually happening when they type a password into a WiFi network.

WiFi is a family of wireless networking standards, maintained by the WiFi Alliance, built on top of the IEEE 802.11 technical standards. It operates on radio waves, specifically in the 2.4GHz, 5GHz, and increasingly 6GHz frequency bands. It is a local area network technology: it connects devices to each other and to a router that provides internet access, but the WiFi signal itself does not travel far beyond your home or office.

The short answer

WiFi works by using radio waves to send data between your devices and a router. Your router is connected to the internet via a wired connection. When you send data over WiFi, your device encodes it onto radio waves at a specific frequency, the router receives it, translates it back into data, and passes it along to the internet. The same process works in reverse for incoming data. Both the router and your devices follow the same communication rules (the 802.11 standard) so they can understand each other.

The full picture

The physical layer: radio waves

Everything WiFi does starts with radio waves. Radio waves are electromagnetic radiation, the same phenomenon as light, X-rays, and gamma rays, but at different frequencies and wavelengths. WiFi uses frequencies between 2.4GHz and 7.2GHz depending on the standard and regulatory region.

When you send data over WiFi, your device takes the digital data (a sequence of ones and zeros) and converts it into radio waves using a technique called modulation. Different WiFi standards use different modulation schemes. WiFi 6 (802.11ax), the current mainstream standard, uses a technique called OFDMA (orthogonal frequency division multiple access), which divides each channel into many smaller subchannels and allows multiple devices to transmit simultaneously on the same channel, dramatically improving efficiency in crowded environments.

The 2.4GHz band is the original WiFi frequency. It has three non-overlapping channels (1, 6, and 11 in the US), which is why you will sometimes see router advice to change your channel if you are getting interference. The 2.4GHz band travels roughly 150 feet indoors and passes through walls reasonably well, which made it great for early home networking. It is also the band used by microwaves, some cordless phones, and Bluetooth devices, which is why you sometimes get interference from your kitchen.

The 5GHz band, introduced with 802.11n (WiFi 4), offers more non-overlapping channels and much faster theoretical speeds. It does not pass through walls as well and has shorter range, which sounds like a disadvantage but actually means less interference from your neighbors. Most modern devices connect to 5GHz when close to the router and fall back to 2.4GHz when they move farther away.

WiFi 6E and WiFi 7 introduced the 6GHz band, which is even faster and has an enormous amount of available spectrum, meaning much less competition from neighbors. The tradeoff is that 6GHz signals behave more like light: they travel shorter distances and are stopped by walls and floors much more readily.

How devices find and connect to a network

When your phone or laptop is looking for a WiFi network, it is performing what is called a scan. In an active scan, your device broadcasts a probe request on each WiFi channel, and any router in range that matches the requested network name (the SSID) responds with a probe response containing information about the network. In a passive scan, your device simply listens for beacon frames that routers transmit periodically.

The SSID is the name of your network. It is broadcast in those beacon frames, which is why people nearby can see your network name on their device. You can disable SSID broadcasting, but this is not a security measure: anyone determined to find your network can use a scanner to detect it regardless.

Once your device has found the network, it needs to authenticate and associate. Authentication in the WiFi sense is simply the process of proving you have the right credentials to join the network. This is separate from security encryption, which comes after association.

WiFi security: what the acronyms actually mean

WiFi security has evolved significantly over the years, and you have probably encountered the acronyms without knowing what they mean.

WEP (Wired Equivalent Privacy) was the original WiFi security standard, introduced in 1997. It is now completely broken. It can be cracked in minutes with freely available tools. If your router still offers WEP as an option, upgrade immediately.

WPA (WiFi Protected Access) replaced WEP and was itself replaced by WPA2. WPA2, specifically WPA2-PSK (Pre-Shared Key), is what most home networks use today. It uses a password you enter to generate encryption keys that protect all data on the network. It is secure against casual attacks and requires significant effort to crack.

WPA3, introduced in 2018, is the current standard. It offers improved security: even if someone captures your encrypted traffic and guesses your password offline, they cannot decrypt it easily. It also makes password guessing harder by using a more secure handshake method. Most devices manufactured after 2019 support WPA3.

For home networks, the security setup works like this: you set a password on your router. That password becomes the pre-shared key. When a device connects, both the router and the device use that key to establish an encrypted tunnel. Anyone who knows the password can join the network and see traffic intended for other devices on the network, which is why you should not share your password with people you do not trust completely.

The role of the router

The router is the center of your home network. It has several jobs: managing traffic between your home devices and the internet (routing), assigning IP addresses to devices that connect (DHCP), translating between your local network addresses and the public internet address your ISP provides (NAT), and broadcasting the WiFi signal (the access point function).

When you connect to WiFi, your router gives your device a local IP address, typically something like 192.168.1.100. This address is only meaningful inside your home network. When your device sends data to the internet, the router rewrites the source address to the public IP address your ISP provides. When the response comes back, the router reverses this. This process, called Network Address Translation, is what allows multiple devices in your home to share one internet connection.

Mesh WiFi systems work differently. Rather than one router covering your whole home, they use multiple access points that communicate with each other wirelessly to create a seamless network across a larger area. The main unit connects to your modem; satellite units placed around your home pick up the signal and rebroadcast it, extending coverage without running cables. The devices connected to a mesh network typically switch automatically between nodes as you move around, though this handoff process varies in quality between manufacturers.

What affects your WiFi speed

Your actual WiFi speed depends on several things at once. The WiFi standard your router and devices support determines the theoretical maximum: WiFi 5 tops out around 3.5Gbps (though real-world speeds are much lower), WiFi 6 reaches roughly 9.6Gbps, and WiFi 7 can exceed 40Gbps in ideal lab conditions.

The distance between your device and the router matters a lot. WiFi signal weakens with distance and with obstacles, particularly walls, floors, and large metal objects (mirrors and appliances can also interfere significantly). The 2.4GHz band travels farther; the 5GHz and 6GHz bands degrade faster.

Congestion is the other major factor. If many devices in your home are using WiFi simultaneously, or if your neighbors are on the same channels, performance drops. This is a shared medium problem: everyone within radio range shares the same airwaves. Newer WiFi standards handle this better (WiFi 6’s OFDMA is particularly good at managing multiple simultaneous connections), but the physical limitation is real.

Why it matters

WiFi is now critical infrastructure in most homes and offices. Understanding what it actually is helps when things go wrong, and they do go wrong.

Most WiFi problems fall into a few categories. Slow speeds usually mean the router is too far away, there is too much interference from neighbors or devices, or the internet connection itself is the bottleneck. Devices connecting but not getting internet usually means the router is working but the internet connection (from your ISP) is down. Intermittent dropping suggests heat buildup in the router, firmware problems, or congestion issues.

The location of your router matters more than most people realize. Putting it in a closet, in a corner of the house far from where you use WiFi, or near a microwave will noticeably degrade performance. Central location, elevated position, away from interference sources. For large homes, mesh systems or access points are usually better solutions than a single powerful router.

Security is also genuinely important. An open WiFi network (no password) means anyone nearby can see the traffic from your devices, including any unencrypted data. In 2026, WPA2 is still the minimum acceptable security; WPA3 is the target. You should also know that the WiFi password protects your network from casual unauthorized use, but it does not protect you from someone who knows the password intercepting traffic between your devices and the router.

Key terms

SSID The network name that identifies your WiFi network. Broadcast in beacon frames, visible to any device scanning for networks.

WPA3 / WPA2 The security protocols that encrypt traffic on your WiFi network. WPA3 is the current standard; WPA2 is the previous generation and still widely used.

2.4GHz / 5GHz / 6GHz The radio frequency bands used by different generations of WiFi. 2.4GHz is slower but travels farther and through walls. 5GHz is faster with shorter range. 6GHz is the newest band and fastest, with shortest range.

OFDMA Orthogonal frequency division multiple access. Used in WiFi 6 and later to allow multiple devices to transmit simultaneously on the same channel, improving efficiency in crowded environments.

Mesh network A WiFi system using multiple access points that communicate with each other to provide seamless coverage over a larger area than a single router can cover.

NAT Network Address Translation. The process by which a router shares one public IP address among multiple devices on a local network. This is what makes home networking work with a single ISP connection.

SSID broadcast The process by which a router announces its presence by transmitting the network name. Can be disabled for privacy, though it does not make the network truly hidden.

Common misconceptions

WiFi and internet are the same thing. WiFi is a way to connect devices to a local network wirelessly. The internet is the global network those devices connect to through the router. You can have WiFi without internet (a local network with no external connection) and internet without WiFi (a wired ethernet connection).

A longer WiFi password is more secure against cracking. WPA2/WPA3 cracking requires capturing the handshake between your device and router and then doing offline computation to guess the password. A longer, more complex password does help. However, the bigger practical risk is someone using your actual WiFi password because you shared it, or brute-forcing it via the online login page of the router itself. Strong router admin passwords and WPA3 matter more than WiFi password length for most people.

Closing your router at night saves power meaningfully. Router power consumption is typically 5 to 20 watts. Closing it does not save enough electricity to matter financially. It does interrupt ongoing network activity and any scheduled tasks (backups, updates, smart home automations). The electromagnetic exposure argument is not supported by evidence.

A WiFi mesh system always outperforms a single router. In a small apartment, a good single router is usually faster than a mesh system at the same price point. Mesh systems win on coverage, not speed. A $300 single router will typically outperform a $300 mesh system in raw throughput. Mesh wins when you need coverage across a large area where a single router signal does not reach.