How the Internet Works

Introduction

• The internet is responsible for the transmission of data, such as videos, over long distances.
• Understanding the journey of data from a data center to your device is key to grasping how the internet works.

Data Centers

• Videos are stored in data centers, which can be located thousands of miles away.
• Data is typically stored in solid-state devices (SSDs) within the data center servers.

Data Transmission Methods

Satellites

• A common method might involve sending signals to satellites.
• Satellites are located about 22,000 miles above the earth, resulting in a total travel distance of 44,000 miles.
• This long distance causes significant latency, making it impractical for most internet applications.

Optical Fiber Cables

• Data is primarily transmitted via a complex network of optical fiber cables.
• Devices connect through cellular data or Wi-Fi routers, ultimately linking to optical fiber networks.

Understanding IP Addresses

• Every device connected to the internet has a unique IP address, serving as its identification.
• IP addresses function like home addresses, allowing data to be delivered accurately.
• The server also has an IP address, and domain names (e.g., youtube.com) are used to simplify access.
• Host headers may be used when multiple websites are stored on the same server.

Domain Name System (DNS)

• The DNS acts as the internet's equivalent of a phone book, mapping domain names to IP addresses.
• Internet service providers (ISPs) manage DNS servers, facilitating the resolution of domain name requests.

Data Request Process

1. User enters domain name in browser.
2. Browser requests the corresponding IP address from the DNS server.
3. With the IP address, the browser sends a request to the server in the data center.
4. The server responds by transmitting data in the form of light pulses through optical fiber cables.

Optical Fiber Network

• Optical fiber cables are laid across the seabed, creating a global network.
• The network is maintained by global companies that manage these cables.
• Light signals are converted to electrical signals at the router, and then transmitted to the device via Ethernet or cellular signals.

Management of the Internet

• ICANN (Internet Corporation for Assigned Names and Numbers) oversees IP address assignment and domain registration.

Data Transmission Efficiency

• Data is sent as binary (zeros and ones) in packets.
• Each packet includes bits of data, sequence numbers, and addresses for routing.
• Packets can take different routes to the destination and are reassembled based on their sequence numbers.
• Acknowledgments are sent for lost packets to ensure complete data transfer.

Protocols

• Protocols manage the flow of data packets, ensuring proper routing and addressing.
• Different protocols are used for various applications to maintain efficient communication.

Conclusion

• The video provides a comprehensive overview of internet operation, focusing on the journey of data packets from data centers to devices.
• Support the creators on patreon.com.