Wifi uses radio frequencies to send data wirelessly between your devices and router. When you're sending an email, your computer encodes it into a digital signal and uses its wifi radio to transmit the message to your router. Your router then sends the encoded email to your modem, which translates the digital data into an electrical signal for transmission to the internet through your internet service provider (ISP).
When you receive information, the process works in reverse. The router receives information from the internet, translates it to a radio signal, and sends it to your device's wireless adapter.
How does wifi transmit data?
Instead of sending packets of data through cables and wires, wifi uses radio frequencies to send signals between devices. The frequency bands for wifi are 2.4 GHz, 5 GHz, and 6 GHz, which are subdivided into channels. This puts wifi communication in a much higher range than cell phone and television frequencies, meaning the signal can carry more data.
A governing body called the IEEE sets the standards for networking transmission methods, with 802.11 being the standard for wifi. In their most recent protocol releases, speed has increased over time, greatly improving data transmission rates. This is largely because newer devices have access to more wifi channels that are less vulnerable to interference.
What's a router?
A router connects all your devices to the internet over the same network. The router receives a digital signal from your modem or ONT and shares it with devices in your home, creating a local area network (LAN).
To connect devices on the network to the internet, routers must be connected to a modem or ONT. When your modem or ONT gets information from the internet, your router distributes that information to your devices wirelessly and over Ethernet. The same process works in reverse when you're sending information out to the internet.
What's a modem?
A modem connects you to the internet by translating the digital data of your computer into an analog signal that can be transmitted over telephone or cable lines.
Your ISP modem connects to either a cable port or telephone socket on the wall, based on your service type. In a typical setup, data travels from your computer to a router, through a modem, and out to the internet over a phone or cable line.
What's an ONT?
If you have fiber internet service, you'll have a device called an optical network terminal (ONT) instead of a modem. An ONT converts the digital signal from your router into an optical signal (light).
What's an ISP?
An internet service provider is a company that charges a recurring fee to provide you with internet access. Customers can receive internet service using a phone line (dial-up), broadband (cable or DSL), fiber, or satellite connection.
ISPs generally offer multiple options for connecting to the internet. These options may be bundled with other services like mobile data or landlines, and they're characterized by different speeds, data limits, and prices.