How does the Internet work ?

When an Internet user is trying to access a web site, the first thing the computer will initiate is a communication with the server hosting the website located in a data center by sending a request. 

This “request” is a data that will be translated to a series of 1s and 0s (computer language), then will be chopped into chunks called packets.

Each packet will be sent to the wi-fi router via either wireless or cable (ethernet), then eventually, will exit the router to the modem and then to the ISP fiber or coaxial network towards the data center location

The data center, which can be across town or across the world from the end-user, has the requested web page stored inside it. Once the server gets a request to access a particular website, the data flow starts. 

After exiting the modem, the packets that were converted from a digital signal to an analog signal will enter the ISP network, which is in most cases a large number of fiber optic cables that either buried underground (Buried Fiber) or attached to utility poles (Aerial Fiber). 

Each packet will then move through multiple ISP networks, routers and switches towards the final destination where the packets will be reassembled into a coherent message (The original request). 

The network will choose the optimum route for the packet to reach the server based on the distance, the links capacity, and other factors. 

A separate message will go back through the network to confirm a successful delivery and right after, the data flow between the user and the server is established.

source : https://broadbandusa.ntia.doc.gov/sites/default/files/2022-12/Introduction_to_Broadband_and_High_Speed_Internet_FINAL_0.pdf