When you visit a website, your device sends a request across the internet to a server, a powerful computer that stores the website's files. That request travels through many different networks, hopping between routers until it reaches the right server, usually taking well under a second.
Before your browser can find the server, it needs to translate the website's name into an IP address using the Domain Name System, or DNS, which works like a phone book for the internet. Once your device knows the address, it can request the actual page.
Data doesn't travel as one single piece — it gets broken into small chunks called packets, which can each take different paths across the network before being reassembled in the correct order once they arrive. This packet-based system makes the internet fast, flexible, and resistant to individual network failures.