Internet

1) What is Internet

• World’s most popular computer network
• Began as an academic research project in 1969 then became global commercial network in 1990s
• It is Decentralization. No one owns the internet or controls its
• Thousands of different organizations operate their own networks and negotiate voluntary interconnection agreements.
• People access internet content using a web browser.
• Internets application: Web, email, BitTorrent

2) Who Runs Internet

• No one runs the internet.
• It’s organized as a decentralized network of networks.
• Thousands of companies, universities, governments, and other entities operate their own networks and exchange traffic with each other based on voluntary interconnection agreements.
• The shared technical standards that make the internet work are managed by an organization called the Internet Engineering Task Force
• The Internet Corporation for Assigned Names and Numbers (ICANN) is responsible for internet governance.
• ICANN is in charge of distributing domain names (like vox.com) and IP addresses.
• But ICANN doesn’t control who can connect to the internet or what kind of information can be sent over it.

3) What’s an IP address?

• Internet Protocol addresses are numbers that computers use to identify each other on the internet.
• IP address differentiate between different computers, routers, and websites
• An IP address is a string of numbers separated by periods. IP addresses are expressed as a set of four numbers — an example address might be 192.158.1.38. Each number in the set can range from 0 to 255. So, the full IP addressing range goes from 0.0.0.0 to 255.255.255.255.
• An IP address is a unique address that identifies a device on the internet or a local network. IP stands for "Internet Protocol," which is the set of rules governing the format of data sent via the internet or local network.
• The use of IP addresses typically happens behind the scenes. The process works like this:
• Your device indirectly connects to the internet by connecting at first to a network connected to the internet, which then grants your device access to the internet.
• When you are at home, that network will probably be your Internet Service Provider (ISP). At work, it will be your company network.
• Your IP address is assigned to your device by your ISP.
• Your internet activity goes through the ISP, and they route it back to you, using your IP address. Since they are giving you access to the internet, it is their role to assign an IP address to your device.
• However, your IP address can change. For example, turning your modem or router on or off can change it. Or you can contact your ISP, and they can change it for you.
• When you are out and about – for example, traveling – and you take your device with you, your home IP address does not come with you. This is because you will be using another network (Wi-Fi at a hotel, airport, or coffee shop, etc.) to access the internet and will be using a different (and temporary) IP address, assigned to you by the ISP of the hotel, airport or coffee shop.

4) What is the difference between IPv6 and IPv4?

• IPv4 and IPv6 are both protocols used to identify devices on a network and route data packets between them.
• IPv4 addresses are 32 bits long, while IPv6 addresses are 128 bits long.
• IPv4 addresses are represented in dotted-decimal notation, while IPv6 addresses are represented in hexadecimal notation with colons separating the different sections.
• IPv6 has a different packet header format from IPv4 and includes built-in encryption and authentication capabilities.

• IPv6 adoption has been slow due to the large number of legacy systems still using IPv4.
  5) How does internet work?

• The Internet is a global network of interconnected computer networks that use standardized communication protocols to connect billions of devices worldwide. The following are the basic steps involved in how the internet works:

• Data Transmission: When a user wants to access a website or send an email, their device (e.g., computer, smartphone, tablet) sends a request to their Internet Service Provider (ISP). The ISP then sends the request to the appropriate web server or email server.

• Routing: The request is then routed through various networks, which may include local area networks (LANs), wide area networks (WANs), and the Internet backbone. Each network consists of routers, which are special computers that direct traffic between networks.

• Domain Name System (DNS): Before a request can be sent to a web server, the user's device needs to know the IP address of the server. This is where the Domain Name System (DNS) comes in. DNS is like a phone book that maps domain names (e.g., google.com) to IP addresses (e.g., 216.58.194.174).

• Request Handling: Once the user's device has the IP address of the web server, it sends the request to the server. The server then processes the request, retrieves the requested data (e.g., a webpage), and sends it back to the user's device.

• Transmission Control Protocol/Internet Protocol (TCP/IP): TCP/IP is the set of protocols that governs how data is transmitted over the Internet. TCP ensures that data is delivered correctly and in the correct order, while IP ensures that data is sent to the correct destination.

• Encryption and Security: To ensure the privacy and security of data transmitted over the Internet, encryption protocols (e.g., HTTPS) are used to encrypt data before it is sent and decrypt it upon receipt.

• Overall, the Internet works by transmitting data between devices through various networks using standardized communication protocols and routing methods.

6) How does wireless internet work

• Wireless internet (also known as Wi-Fi) works by using radio waves to transmit data between a device and a router. Here are the main points of how wireless internet works:
• A device, such as a smartphone or laptop, connects to a wireless router using a Wi-Fi network adapter.
• The device and router communicate with each other using radio waves, which are a type of electromagnetic radiation.
• The router sends and receives data from the device using radio waves that are transmitted on specific frequencies.
• The data is then sent over the internet using the same protocols used for wired internet connections.
• The range of a wireless network depends on factors such as the power of the router, the frequency used, and any physical barriers that may interfere with the signal.
• Security measures, such as WPA2 encryption and password protection, are used to protect wireless networks from unauthorized access.

• Overall, wireless internet works by using radio waves to transmit data between a device and a router, allowing users to connect to the internet without the need for physical cables.
  7) How does cellular internet work

• Mobile devices connect to cellular networks using cellular radios that communicate with nearby cell towers.

• Data is transmitted over the network using various technologies like 3G, 4G, or 5G.

• Data is then sent over the internet using the same protocols used for wired and wireless internet connections.

• Cellular internet is typically offered by mobile service providers and charged based on data usage.

8) Cloud

• The cloud refers to a network of remote servers that are accessed over the internet to store, manage, and process data instead of using a local server or personal computer.
• Cloud services provide users with access to computing resources, applications, and storage on demand, without the need to invest in and manage their own infrastructure.
• Here are some of the key characteristics of cloud computing
• The cloud is a network of remote servers accessed over the internet to store, manage, and process data.
• Cloud services provide users with access to computing resources, applications, and storage on demand.
• Cloud computing offers on-demand self-service, broad network access, resource pooling, rapid elasticity, and measured service.
• Cloud computing is popular due to its flexibility, scalability, and cost-effectiveness.
• Examples of cloud services include cloud storage, cloud hosting, and cloud-based applications.

10) What are Packets

• In computer networking, a packet is a unit of data that is transmitted over a network.
• Packets contain information such as the source and destination addresses, data payload, and protocol information.
• Networks use packets to send and receive data between devices, such as computers or routers.
• Packets are typically transmitted in a serial manner, with each packet being sent and received individually.
• Packets are the fundamental building blocks of modern computer networks, enabling devices to communicate and share data over vast distances.

11) What is World Wide Web

• The World Wide Web (WWW or Web) is a system of interconnected hypertext documents and resources linked through the internet.
• The Web was invented by Sir Tim Berners-Lee in 1989 as a means of sharing scientific information.
• The Web uses a standardized protocol called HTTP (Hypertext Transfer Protocol) to enable the transfer of data and resources across the internet.
• Web documents are typically written in HTML (Hypertext Markup Language) and can include multimedia content such as images, audio, and video.
• Web browsers like Google Chrome, Mozilla Firefox, and Microsoft Edge are used to access and view Web documents.

• The Web has grown to become a vast and decentralized network of information and resources, connecting people and organizations across the globe
  12) What is a Web browser

• Web browsers are software applications that allow users to access and view web pages on the internet.

• Browsers use standardized protocols such as HTTP and HTTPS to communicate with web servers and transfer data.

• Browsers can render a wide range of content types, including text, images, video, audio, and interactive applications.
  13) SSL

• SSL, short for Secure Sockets Layer, is a family of encryption technologies that allows web users to protect the privacy of information they transmit over the internet.

• SSL is a security protocol that encrypts data transmitted over the internet to protect it from unauthorized access.

• SSL uses digital certificates to authenticate the identity of websites and ensure that data is being transmitted securely.

• SSL creates a secure connection between a user's web browser and a web server, preventing third parties from intercepting or tampering with data.

• SSL has been replaced by TLS (Transport Layer Security) as the preferred security protocol for web communications.

• SSL and TLS are commonly used to secure online transactions, such as credit card payments and online banking, and to protect sensitive data such as passwords and personal information.

14) What is Domain Name system

• The Domain Name System (DNS) is a hierarchical decentralized naming system used to associate domain names, such as example.com, with numerical IP addresses, such as 192.0.2.1. DNS allows internet users to access websites using easy-to-remember domain names instead of having to remember the IP addresses of every website they want to visit.
• Here are some additional points about DNS:
• DNS is responsible for translating domain names into IP addresses that computers can use to connect to websites and other online resources.
• DNS servers are distributed around the world and work together to manage the global domain name system.
• DNS operates using a tree-like hierarchy, with the root domain at the top, followed by top-level domains (such as .com, .org, and .net), and then subdomains.
• DNS uses a variety of record types, such as A records, CNAME records, and MX records, to store information about domain names and their associated IP addresses.
• DNS plays a critical role in the functioning of the internet, allowing users to access millions of websites and online resources with ease.

15) How web works

• The World Wide Web (WWW) is a collection of interconnected documents and resources that can be accessed over the internet using web browsers. Here are the basic steps of how the web works:
• A user opens a web browser and enters a URL (Uniform Resource Locator) or clicks a hyperlink to access a website.
• The browser sends a request to the web server hosting the website, asking for the resources needed to display the web page.
• The web server receives the request and searches for the requested resources, such as HTML files, CSS stylesheets, and JavaScript files.
• The web server sends the requested resources back to the browser in the form of HTTP (Hypertext Transfer Protocol) responses.
• The browser receives the responses and uses the HTML and CSS files to render the web page on the user's device.
• If the web page contains JavaScript code, the browser executes the code to add interactivity and dynamic behavior to the page.
• The user can interact with the web page by clicking hyperlinks, filling out forms, or triggering other events that send new requests to the web server.
• The web server responds to these requests by sending back the resources needed to update the web page, and the cycle repeats.
• Overall, the web works by allowing users to access and view interconnected resources using web browsers, which communicate with web servers to request and receive the resources needed to render web pages.