Come funziona internet?

KEIS - Keep It Simple

16 Apr 202105:00

Summary

TLDRThe video script narrates the evolution of the internet from its early beginnings with ARPANET in 1969 to the invention of the World Wide Web by Tim Berners-Lee in 1989. It explains how data transmission has transformed communication globally, detailing the technical process of how data packets are sent and received across the internet, including the roles of modems, routers, and IP addresses in facilitating data exchange between devices.

Takeaways

🌐 The Internet allows global communication and information exchange through computers, which has revolutionized the way we communicate.
🔗最初，程序员只能在同一房间内的计算机之间通过直接连接的电缆发送数据，这种连接称为局域网（LAN）。
🚀 In 1969, the United States Department of Defense created ARPA (Advanced Research Projects Agency) to facilitate information exchange between computers across the country, leading to the creation of ARPANET.
🌍 1989年，英国物理学家Tim Berners-Lee在欧洲核子研究组织（CERN）工作时，提出了一个全球网络的想法，用于组织科学家之间的信息交流。
🌐 Berners-Lee在1991年8月6日公开了世界上第一个网站，这标志着万维网（World Wide Web）的诞生。
🔄 互联网是由许多计算机点组成的网络，这些点通过共同的规则交换数据，形成了我们今天所知的互联网。
📦 访问网站时，数据从我们的设备通过调制解调器（modem）传输，经过多个路由器（routers）和互联网服务提供商（ISPs），最终到达托管网站的服务器。
📨 数据在传输过程中被分割成数据包，每个数据包都包含目的地和组装指令的信息。
🔄 路由器通过添加自己的IP地址来帮助数据包找到通往目标计算机的路径。
🔄 当服务器返回信息时，它创建具有相同封装的数据包，这些数据包在返回途中通过每个路由器时逐渐解封装，直到到达我们的计算机。
🌐 互联网不仅仅是一个概念上的“云”，它实际上是地面下的光纤网络，这是数据传输的主要途径。

Q & A

What was the initial capability of computer programmers in terms of data transfer?
-Initially, computer programmers were able to send data from one computer to another in the same room using a cable that directly connected the two.
What is the term for the type of connection used by early computers within the same room?
-This type of connection is known as a Local Area Network (LAN).
What was the purpose of the Advanced Research Projects Agency (ARPA) created by the United States Department of Defense in 1969?
-ARPA aimed to enable the exchange of information between computers scattered across the United States by creating a network called ARPANET.
Who is credited with the invention of the World Wide Web, and in what year did this occur?
-English physicist Tim Berners-Lee is credited with the invention of the World Wide Web in 1989.
What was Tim Berners-Lee's profession when he developed the idea for the World Wide Web?
-Tim Berners-Lee was a technician at CERN when he developed the idea for the World Wide Web.
How did the World Wide Web initially function?
-The World Wide Web was initially designed as a mesh that allowed navigation through the various contents of the different research laboratories' computer archives, facilitating the organization of information exchanged by scientists within CERN.
What is the significance of August 6, 1991, in the history of the Internet?
-On August 6, 1991, Tim Berners-Lee made the first website in the world public, marking a significant milestone in the history of the Internet.
How does the Internet physically connect computers around the world?
-The Internet is a network of computers connected to each other, exchanging data through a series of common rules. It includes a hidden filament in the ground that corresponds to the main data transmission pathway.
What role does a modem play in connecting to the Internet?
-A modem allows digital signals to travel along telephone lines, facilitating the transmission of data from one device to an Internet Service Provider (ISP).
How do routers assist in directing data to the correct destination on the Internet?
-Routers help by dividing data into packets, which are then reassembled upon reaching their destination. They add their own IP address to the packet, which is added to each time it reaches a new router, until it reaches the server hosting the desired website.
What is the purpose of IP addresses in the context of the Internet?
-IP addresses are unique identifiers for devices on the Internet, allowing data to be correctly directed to and from the intended destinations, whether they are computers, servers, or other networked devices.

Outlines

00:00

🌐 The Evolution of Internet and Networking

This paragraph discusses the history and development of the internet. It begins by mentioning the early days of computers when programmers could only send data from one computer to another in the same room through a direct cable connection, known as a Local Area Network (LAN). The script then moves on to the creation of ARPANET by the Advanced Research Projects Agency (ARPA) in 1969, which aimed to facilitate information exchange between computers across the United States. The paragraph highlights the significant contribution of English physicist Tim Berners-Lee, who refined the original idea and invented the World Wide Web in 1989 while working at CERN. His invention allowed for the organization of information exchanged by scientists within the research laboratories and led to the birth of the first website on August 6, 1991. The paragraph concludes by emphasizing the growth of this computer network into the inspiration for the creation of the internet as we know it today.

Mindmap

Keywords

💡Internet

The Internet is a global network of interconnected computers and servers that allows for the exchange of information and data. It is the backbone of modern communication, enabling the use of services like YouTube, Facebook, and email. In the video, it is highlighted as a network of points (computers) connected by common protocols for data exchange, and serves as the central theme around which the entire explanation of how data is transmitted and received revolves.

💡Local Area Network (LAN)

A Local Area Network, or LAN, is a network that connects computers and devices within a limited area, such as a home, school, or office building. It was the early form of computer networking that allowed data transfer between computers in the same room through a direct cable connection. In the video, it is mentioned as the precursor to the wider internet connectivity, showing the progression from local to global networking.

💡ARPANET

ARPANET, or the Advanced Research Projects Agency Network, was the first network to implement the protocol suite TCP/IP and was the precursor to the modern Internet. Funded by the United States Department of Defense, it was created to allow computers across the United States to exchange information. In the video, ARPANET is described as a web that connected computers scattered across the nation, laying the groundwork for the development of the World Wide Web.

💡Tim Berners-Lee

Sir Tim Berners-Lee is a British computer scientist who is credited with inventing the World Wide Web in 1989. He proposed a global hypermedia project that allowed people to access information available on the internet more easily. In the video, he is portrayed as the individual who perfected the idea of a global network for organizing information exchanged by scientists at CERN, leading to the creation of the first website.

💡World Wide Web

The World Wide Web, often simply called the Web, is a system of interlinked hypertext documents accessed via the Internet. It was invented by Tim Berners-Lee and is a crucial part of the modern Internet experience, allowing for the easy navigation and sharing of information. In the video, the World Wide Web is presented as the innovation that transformed the initial idea of a computer network into the vast, interconnected system we know today.

💡Router

A router is a networking device that forwards data packets between computer networks. It determines the best path for data to travel, allowing information to be sent from one device to another across the Internet. In the video, routers are essential for directing data correctly from the user's computer to the server hosting the desired website, by adding their IP addresses to the data packets as they pass through the network.

💡IP Address

An IP, or Internet Protocol, address is a unique numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication. It serves two main functions: identifying the host or network interface and providing the location of the host in the network. In the video, IP addresses are likened to envelopes containing destination and assembly instructions for data packets, allowing them to be correctly delivered to their intended recipients.

💡Data Packets

Data packets are units of data that are transmitted over a network. They are the fundamental building blocks of data communication over the Internet. Each packet contains a portion of the data to be sent, along with control information. In the video, data packets are described as being divided and reassembled, with their journey through the Internet involving multiple routers and the addition of IP addresses to ensure accurate delivery.

💡Modem

A modem is a device that modulates and demodulates digital signals to allow communication over analog networks, such as telephone lines or radio frequencies. It enables the transmission of digital data over these networks by converting digital signals into analog signals for transmission and then converting them back into digital upon receipt. In the video, the modem is part of the process that allows data to be sent from our computer or smartphone to the Internet service provider.

💡Smartphone

A smartphone is a mobile device that combines the functions of a cell phone with advanced features of a computer, allowing users to access the Internet, send emails, take photos, use apps, and more. In the video, the smartphone is used as an example of a device that can connect to the Internet via Wi-Fi or mobile networks to access websites and services.

💡Information Exchange

Information exchange refers to the process of sharing data or information between different entities or systems. In the context of the Internet and the video, it is the fundamental purpose of the network, enabling the transfer and sharing of vast amounts of data across the globe. The video emphasizes the importance of information exchange in the development of the Internet, from its early beginnings with ARPANET to the World Wide Web.

Highlights

The Internet allows for global communication and information exchange.

Computers initially could only send data to another within the same room through a direct cable connection, known as a Local Area Network (LAN).

In 1969, the United States Department of Defense created ARPA, aiming to facilitate information exchange between computers across the country.

ARPANET was the first network known as a web in English, enabling the exchange of information over a wide area.

Tim Berners-Lee, an English physicist, refined the idea of a global network in 1989 while working at CERN.

The World Wide Web was invented to organize information exchanged by scientists within CERN.

The first website in the world was made public by Tim Berners-Lee on August 6, 1991.

The computer network has grown over the years, inspiring the creation of the Internet as we know it today.

The Internet can be thought of as a series of points, or computers, connected and exchanging data following common rules.

The Internet is not a cloud but a physical network of cables underground, representing the main data transmission pathway.

When visiting a website, data is transmitted from the modem through telephone lines to reach an Internet Service Provider (ISP).

Smartphones connect to the Internet through mobile antennas and communicate with ISPs via a mobile interface.

Routers are necessary to direct data correctly from the computer to the server using the network.

Data is divided into packets and reassembled upon reaching the destination computer.

All devices connected to the Internet, including phones, computers, and servers, have an IP address for data routing.

Data packets are sent using the IP address of the destination computer, with each router adding its own IP address.

The server returns information in packets with a similar envelope, while the packet makes its way back to the original computer.

Each router peels off a layer of the packet to discover where to send the next packet until it reaches the destination computer.

The Internet is a network of many points connected to each other, allowing us to navigate and connect with anyone in the world.