Here is a concise summary of how the internet works based on the provided text:
**Overview**
* The internet connects devices worldwide, enabling data exchange between servers, computers, and mobile phones.
* Data transmission occurs through a complex network of **optical fiber cables**, not satellites, to minimize latency.
**Key Process Steps**
1. **Request**: You enter a **domain name** (e.g., youtube.com) into your browser.
2. **Domain Name System (DNS)**: Your browser sends the request to a DNS server, which translates the domain name into an **IP Address**.
3. **Data Retrieval**: The IP Address is used to forward the request to a **server** in a **data center**.
4. **Data Transmission**: The server sends the requested data (e.g., a video) through **optical fiber cables** as **light pulses**.
5. **Routing**: Data is divided into **packets**, each containing sequence numbers and IP addresses, and routed independently to the destination device.
6. **Reassembly**: Packets are reassembled at the destination device (e.g., your phone or laptop) based on sequence numbers.
**Additional Key Concepts**
* **IP Addresses**: Unique identifiers for devices on the internet.
* **Protocols**: Set rules for data packet management, ensuring efficient and correct data transmission.
* **Network Management**: Organizations like ICANN manage global internet infrastructure, including IP address assignments and domain name registrations.
Here are the key facts extracted from the text, numbered and in short sentences:
**Internet Infrastructure**
1. The internet uses a network of optical fiber cables to transmit data.
2. These cables can be laid under the sea or across land, including hilly areas.
3. Global companies are responsible for laying and maintaining these cable networks.
**Data Centers and Servers**
4. Data centers store websites and other online content on solid-state devices (SSDs).
5. Servers within data centers are powerful computers that provide access to stored content.
6. Each server has a unique IP address.
**IP Addresses and Domain Names**
7. Every internet-connected device has a unique IP address (a string of numbers).
8. IP addresses are used to identify devices on the internet, similar to home addresses.
9. Domain names (e.g., youtube.com) correspond to IP addresses for easier remembrance.
10. DNS (Domain Name System) servers act as "phone books" to match domain names with IP addresses.
**Data Transmission**
11. Data is transmitted through optical fiber cables in the form of light pulses.
12. Data is chopped into small "packets" for efficient transmission.
13. Each packet contains the data (e.g., video bits), sequence number, and source/destination IP addresses.
14. Packets can take different routes to reach their destination.
15. Upon arrival, packets are reassembled according to their sequence number.
**Internet Management**
16. ICANN (Internet Corporation for Assigned Names and Numbers) manages IP address assignments, domain name registrations, etc.
17. Protocols (sets of rules) manage the complex flow of data packets across the internet.
18. Different applications use different protocols for data transmission.
**Miscellaneous**
19. Satellites are not typically used for internet data transmission due to significant latency (delay).
20. The distance a satellite signal would need to travel (approximately 44,000 miles) causes unacceptable latency.