How does the internet work? (Full Course)

The video script introduces a course designed for individuals without technical knowledge, aiming to demystify the workings of the internet. The instructor, Frost, uses visual aids to teach the basics and assumes no prior knowledge from the students. The course covers the fundamentals of the internet, including its infrastructure, the role of Internet Service Providers (ISPs), and the concept of a Local Area Network (LAN). It also touches on the use of switches and cables to enable communication between computers within an office environment and invites learners to embark on a visual journey to understand internet concepts.

The paragraph explains how to create a Local Area Network (LAN) using switches and access points. It details the use of copper cables, such as Cat 5 or Cat 6, for connecting computers to a switch within a home or office setting. The distinction between switches, which use cables, and access points, which utilize wireless technology, is clarified. The importance of using the appropriate cable type with switches is emphasized, and the concept of a LAN as a restricted area network is introduced. The communication process between computers within the same network is also described.

The script delves into how computers can connect to the internet, highlighting the necessity of a router for this purpose. It outlines the process of connecting a switch to a router and the need for an internet service provider (ISP) to facilitate the connection. The router's function as a gateway to the internet is explained, and the video hints at exploring the communication of computers with the internet in subsequent lessons.

This section focuses on the basic tasks of switches and routers, emphasizing their roles in enabling communication within a local area network (LAN) and between different networks, respectively. It illustrates how packets are sent from one computer to another within the same LAN and how routers direct these packets to their destinations based on routing tables. The importance of routers in connecting to the internet is also highlighted.

The script provides a simplified model to visualize the internet, explaining that the internet is a network of networks, connecting millions of local area networks (LANs) worldwide. It discusses the necessity of routers in facilitating this vast interconnected system and addresses the question of why multiple routers are used instead of a single one. The advantages of a distributed structure, including load balancing and avoiding a single point of failure, are explained.

The paragraph explains the function of home routers, which combine the features of both switches and routers, making them suitable for small environments like homes or small offices. It discusses the use of home routers for internet connectivity, emphasizing that they allow devices to connect to the internet and communicate with each other. The importance of routers in enabling communication with the internet is reiterated.

The script highlights the physical infrastructure of the internet, focusing on the vast network of underwater and land-based cables that facilitate global communication. It underscores the significance of these cables, particularly for intercontinental connections, and notes that the internet's resilience is due to its distributed structure, which prevents a single point of failure.

This section discusses the process of connecting to the internet from a computer's perspective, using the example of streaming a video on Udemy. It explains the concept of streaming as the piece-by-piece delivery of content, such as a video, to a user's computer. The role of the home router in facilitating this process is highlighted, as well as the function of servers in managing the traffic from multiple users.

The script introduces the concept of Wide Area Networks (WANs), particularly Virtual Private Networks (VPNs), which allow for the creation of a secure, private network over a public network like the internet. It explains the use of VPN tunneling and encryption to enhance security, comparing the process to sending a letter in an envelope through a postman. The importance of encryption in protecting data is emphasized.

This paragraph compares Local Area Networks (LANs) created by directly connecting switches with Wide Area Networks (WANs) created using VPN technology. It highlights that LANs are generally more secure because the data does not pass over the public internet. The concept of a private WAN is introduced, contrasting it with public VPNs, and notes that while private WANs offer higher security, they can be costly. The paragraph concludes by emphasizing that switches are used to create LANs, while routers are used to create WANs.

The script explains the hierarchy of ISPs, from local to regional and global, and their roles in facilitating internet connectivity. It details how local ISPs connect neighborhoods, regional ISPs connect cities, and global ISPs connect different countries. The concept of Points of Presence (PoPs) as the physical locations where ISPs house their networking equipment is introduced. The paragraph also discusses the routing of packets through various ISPs and the factors that determine the path a packet takes.

This section discusses the concept of peering, where large companies like Google establish direct connections with ISPs to provide faster access to their servers. It contrasts this with the distributed server model used by companies like Google and Udemy to serve content efficiently worldwide. The benefits of peering in terms of speed, efficiency, and security are highlighted, along with the challenges faced by companies without such infrastructure.

The final paragraph emphasizes the consumer's choice in selecting an Internet Service Provider (ISP) based on their location and service offerings. It outlines the possibility of connecting directly to a regional or global ISP if they provide services in the user's area. The paragraph also suggests that while setting up a local ISP might be an option for some, most users will find it unnecessary and will opt for services from one of the available ISPs in their location.