Have you ever wondered how the internet works? Let’s dive into the fascinating world of web browsing and discover how computers communicate with each other across the globe.
When you want to visit a website, you open a web browser, which is the app that lets you access web pages. You type in the web address, also known as a URL (Uniform Resource Locator), like Tumblr.com, and hit enter. This simple action sets off a complex process where your computer starts talking to another computer called a server, which could be thousands of miles away.
The conversation between your computer and the server happens in a language called HTTP, which stands for HyperText Transfer Protocol. Think of HTTP as the language computers use to request and send documents. When you request a page, your computer sends a “GET” request to the server. For example, if you want to log into Tumblr, your computer sends a GET request for the login page, like GET /login.
Once the server receives your request, it sends back the web page in a language called HTML, or HyperText Markup Language. HTML tells your browser how to display the page, including text, links, and images. If a page has images or videos, each of these elements is a separate file with its own URL, requiring additional HTTP requests to load them.
Sometimes, you need to send information to a website, like when you fill out a form or type a search query. This is done using an HTTP POST request. For instance, when you log in to Tumblr, you send a POST request with your email and password. The server checks your details and sends back a page confirming your login, along with a cookie. This cookie acts like an ID card, helping the website remember you the next time you visit.
The internet is open, which means information is sent in plain text. To keep your data safe, secure websites use SSL (Secure Sockets Layer) and TLS (Transport Layer Security). These are like security guards that protect your information from unauthorized access. When a website uses SSL or TLS, you’ll see a lock icon in your browser’s address bar next to HTTPS, indicating a secure connection.
Behind the scenes, the internet relies on various technologies to function. HTTP and DNS (Domain Name System) manage the sending and receiving of web content like HTML and media files. TCP/IP and router networks break down and transport information in small packets, which travel through electric wires, fiber optic cables, and wireless networks. These packets are made up of binary sequences of 1s and 0s.
Even though the internet is complex, once you understand how one layer works, you can trust that all the layers will work together to deliver information reliably. So, the next time you browse the web, you’ll know a bit more about the magic happening behind the scenes!
Design a simple web page using HTML. Start by creating a basic structure with a title, headings, paragraphs, and a list. Experiment with adding images and links. This will help you understand how HTML is used to structure web content.
Simulate an HTTP GET request by role-playing with classmates. One student acts as the client, requesting a web page, while another acts as the server, responding with HTML content. This activity will help you grasp how HTTP facilitates communication between computers.
Go on a scavenger hunt to find different URLs on the internet. Identify the protocol (HTTP or HTTPS), domain name, and path in each URL. This will reinforce your understanding of how URLs direct you to specific web pages.
Investigate the security features of websites by checking for the lock icon in the browser’s address bar. Discuss with classmates why SSL/TLS is important for protecting data. This will enhance your awareness of internet security practices.
Play a game where you act as data packets traveling through a network. Navigate through obstacles representing routers and switches to reach your destination. This will help you visualize how data is transmitted across the internet.
Sure! Here’s a sanitized version of the transcript:
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[music] I’m Jasmine Lawrence, and I’m a program manager on the Xbox One engineering team. [music] One of our biggest features is called Xbox Live. It’s an online service that connects gamers from all around the world, and we rely on the internet to make that happen. This is no easy task, and there are a lot of things happening behind the scenes. [swish] The internet is totally changing how people interact and connect. But how does it work? How do computers all across the world actually communicate with each other? [music]
Let’s look at web browsing. First, you open a web browser. It’s the app you use to access web pages. Next, you type in the web address, or URL, which stands for Uniform Resource Locator, of the website you want to visit, like Tumblr.com. [synth music]
Hi, I’m David Karp, the founder of Tumblr, and we’re here today to talk about how those web browsers we use every day actually work. So you’ve probably wondered what happens when you type an address into your web browser and then hit enter. It really is quite fascinating. In that moment, your computer starts talking to another computer, called a server, that’s usually thousands of miles away. In milliseconds, your computer asks that server for a website, and that server starts to respond in a language called HTTP, which stands for HyperText Transfer Protocol. You can think of it as the language that one computer uses to ask another computer for a document.
If you were to intercept the conversation between your computer and a web server on the internet, it mainly consists of something called “GET” requests. These are simply the word GET followed by the name of the document you’re requesting. For example, if you try to log into Tumblr and load our login page, you’re sending a GET request to Tumblr’s server that says GET /login. This tells Tumblr’s server that you want all of the HTML code for the Tumblr login page.
HTML stands for Hyper Text Markup Language, and it’s the language used to tell a web browser how to display a page. If you think about something like Wikipedia, which is essentially a large document, HTML is used to format the text, create links, and display images. The text of a web page is included directly in the HTML, but other elements like images or videos are separate files with their own URLs that need to be requested. The browser sends separate HTTP requests for each of these elements and displays them as they arrive.
If a web page has many images, each one causes a separate HTTP request, which can slow down the page loading time. [pops] Sometimes, when you browse the web, you’re not just requesting pages with GET requests. Sometimes you send information, like when you fill out a form or type a search query. Your browser sends this information in plain text to the web server using an HTTP POST request.
For instance, when you log in to Tumblr, the first thing you do is make a POST request to Tumblr’s login page with some data attached, such as your email address and password. That information goes to Tumblr’s server, which verifies your identity and sends a web page back to your browser that says, “Success! Logged in as [Your Name].” Along with that web page, it also attaches a bit of invisible cookie data that your browser saves. This cookie data acts as an ID card for Tumblr, identifying you as a user. The next time you visit Tumblr, your browser automatically includes that ID number with the request it sends to Tumblr’s servers, allowing them to recognize you.
[music] Now, the internet is completely open. All of its connections are shared, and information is sent in plain text. This openness can allow unauthorized individuals to access personal information sent over the internet. However, secure websites prevent this by asking your web browser to communicate over a secure channel using something called Secure Sockets Layer (SSL) and its successor, Transport Layer Security (TLS). You can think of SSL and TLS as a layer of security that protects your communications from unauthorized access or tampering.
SSL and TLS are active when you see a little lock icon in your browser’s address bar next to HTTPS. The HTTPS protocol ensures that your HTTP requests are secure. When a website requests a secure connection, it first provides a digital certificate, which is an official ID card proving its identity. Digital certificates are issued by certificate authorities, trusted entities that verify the identities of websites. If a website tries to establish a secure connection without a properly issued digital certificate, your browser will warn you.
That’s the basics of web browsing—the part of the internet we interact with daily. To summarize, HTTP and DNS manage the sending and receiving of HTML, media files, and other web content. Underneath it all, TCP/IP and router networks break down and transport information in small packets. Those packets are made up of binary sequences of 1s and 0s that are physically sent through electric wires, fiber optic cables, and wireless networks. Fortunately, once you’ve learned how one layer of the internet works, you can rely on it without needing to remember all the details. We can trust that all those layers will work together to deliver information reliably and at scale. [music fades out]
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This version maintains the core information while removing any unnecessary or informal elements.
Internet – A global network of computers that allows people to access and share information. – Example sentence: “Using the internet, students can find resources for their coding projects.”
HTTP – Hypertext Transfer Protocol, a set of rules for transferring files on the web. – Example sentence: “When you type a website address, your browser uses HTTP to fetch the page.”
HTML – Hypertext Markup Language, the standard language used to create web pages. – Example sentence: “Learning HTML is the first step in building your own website.”
Browser – A software application used to access and view websites on the internet. – Example sentence: “Google Chrome is a popular browser for surfing the web.”
Server – A computer system that provides data or services to other computers over a network. – Example sentence: “The server hosts the website and delivers its content to users.”
Request – An action taken by a computer to ask for data or services from another computer. – Example sentence: “When you click a link, your browser sends a request to the server for the webpage.”
Post – A method used to send data to a server, often used in forms on websites. – Example sentence: “When you submit a form, the data is sent to the server using a POST request.”
Secure – Protected from unauthorized access, often used in the context of data transmission. – Example sentence: “Websites use HTTPS to ensure that data sent between the browser and server is secure.”
Data – Information processed or stored by a computer. – Example sentence: “Programmers write code to manipulate data and produce useful results.”
Cookies – Small pieces of data stored on a user’s computer by a web browser while browsing a website. – Example sentence: “Websites use cookies to remember your login information and preferences.”
