Basics of internet
1. How does the Internet work?
The Internet works through a packet routing network in accordance with the Internet Protocol (IP), the Transport Control Protocol (TCP) and other protocols.
What’s a protocol?
A protocol is a set of rules specifying how computers should communicate with each other over a network. For example, the Transport Control Protocol has a rule that if one computer sends data to another computer, the destination computer should let the source computer know if any data was missing so the source computer can re-send it. Or the Internet Protocol which specifies how computers should route information to other computers by attaching addresses onto the data it sends.
What’s a packet?
Data sent across the Internet is called a message. Before a message is sent, it is first split in many fragments called packets. These packets are sent independently of each other. The typical maximum packet size is between 1000 and 3000 characters. The Internet Protocol specifies how messages should be packetized.
What’s a packet routing network?
It is a network that routes packets from a source computer to a destination computer. The Internet is made up of a massive network of specialized computers called routers. Each router’s job is to know how to move packets along from their source to their destination. A packet will have moved through multiple routers during its journey.
What physical infrastructure makes the Internet work?
A lot of different kinds of hardware and infrastructure go into making the Internet work for everyone. Some of the most important types include the following:
· Routers forward packets to different computer networks based on their destination. Routers are like the traffic cops of the Internet, making sure that Internet traffic goes to the right networks.
· Switches connect devices that share a single network. They use packet switching to forward packets to the correct devices. They also receive outbound packets from those devices and pass them along to the right destination.
· Web servers are specialized high-powered computers that store and serve content (webpages, images, videos) to users, in addition to hosting applications and databases. Servers also respond to DNS queries and perform other important tasks to keep the Internet up and running. Most servers are kept in large data centers, which are located throughout the world.
Domain Name
A computer linked to a network has a unique address that identifies it, called an “IP address” (where IP stands for Internet Protocol). It’s an address made of a series of four numbers separated by dots, for example, 192.168.2.10.
That’s perfectly fine for computers, but we human beings have a hard time remembering that sort of address. To make things easier, we can alias an IP address with a human-readable name called a domain name. For example (at the time of writing; IP addresses can change) google.com is the domain name used on top of the IP address 173.194.121.32. So, using the domain name is the easiest way for us to reach a computer over the Internet.
2. What is DNS?
The Domain Name System (DNS) is the phonebook of the Internet. Humans access information online through domain names, like nytimes.com or espn.com. Web browsers interact through Internet Protocol (IP) addresses. DNS translates domain names to IP addresses so browsers can load Internet resources.
Each device connected to the Internet has a unique IP address that other machines use to find the device. DNS servers eliminate the need for humans to memorize IP addresses such as 192.168.1.1 (in IPv4), or more complex newer alphanumeric IP addresses such as 2400:cb00:2048:1::c629:d7a2 (in IPv6).
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How DNS Works in 6 Easy Steps:
- The user logs onto their Internet Service Provider (ISP) to use the Internet.
- The user opens up a web browser (Firefox, Chrome, Internet Explorer, Safari, etc.) and types a URL into the address bar. For example, perhaps the user types in https://www.example.net/.
- The computer then asks for the ISP’s DNS servers for the specific IP address for www.example.net.
- Once the DNS server that holds this specific IP address for www.example.net is found, the DNS server responds with the appropriate IP address and the user’s computer then gives this address to the user’s browser.
- The browser opens a connection to the server using the IP address provided and retrieves the page from the site requested, in this case for www.example.net.
- The browser displays the requested page on the computer screen.
3. What is HTTP?
HTTP stands for Hypertext Transfer Protocol. When you enter http:// in your address bar in front of the domain, it tells the browser to connect over HTTP. HTTP uses TCP (Transmission Control Protocol), generally over port 80, to send and receive data packets over the web.
Communication between client computers and web servers is done by sending HTTP requests and receiving HTTP Responses
4. What is HTTPS?
HTTPS stands for Hypertext Transfer Protocol Secure (also referred to as HTTP over TLS or HTTP over SSL). When you enter https:// in your address bar in front of the domain, it tells the browser to connect over HTTPS. Generally, sites running over HTTPS will have a redirect in place so even if you type in http:// it will redirect to deliver over a secured connection. HTTPS also uses TCP (Transmission Control Protocol) to send and receive data packets, but it does so over port 443, within a connection encrypted by Transport Layer Security (TLS).
HyperText Transfer Protocol Secure (HTTPS) is the secure version of HTTP, the protocol over which data is sent between your browser and the website that you are connected to. The ‘S’ at the end of HTTPS stands for ‘Secure’. It means all communications between your browser and the website are encrypted. HTTPS is often used to protect highly confidential online transactions like online banking and online shopping order forms.
HTTPS transmits its data security using an encrypted connection. Basically, it uses a public key which is then decrypted on the recipient side. The public key is deployed on the server, and included in what you know as an SSL certificate. The certificates are cryptographically signed by a Certificate Authority (CA), and each browser has a list of CAs it implicitly trusts. Any certificate signed by a CA in the trusted list is given a green padlock lock in the browser’s address bar, because it’s proven to be “trusted” and belongs to that domain.
5. How does a web browser work?
A web browser takes you anywhere on the internet. It retrieves information from other parts of the web and displays it on your desktop or mobile device. The information is transferred using the Hypertext Transfer Protocol, which defines how text, images and video are transmitted on the web. This information needs to be shared and displayed in a consistent format so that people using any browser, anywhere in the world can see the information.
When the web browser fetches data from an internet-connected server and it then uses a piece of software called a rendering engine to translate that data into text and images. This data is written in Hypertext Markup Language (HTML) and web browsers read this code to create what we see, hear and experience on the internet. Refer this link for more
6. Web Hosting
Web hosting is an online service that enables you to publish your website or web application on the Internet
