JavaScript powers the interactivity of web browsers. Without browsers like Chrome, Firefox, or Safari, JavaScript wouldn’t have become as popular as it is today. These browsers are built to display web pages, and JavaScript adds life to them by making them interactive.

• JavaScript + Browsers = Web Magic 🎩✨

Browsers have evolved differently over time. Companies added features in different ways, sometimes causing confusion. Eventually, these features were standardized so all browsers could work similarly.

• Browsers are why JavaScript is popular.
• The web’s development hasn’t always been smooth, but it’s what makes the internet unique and flexible!

A network connects computers together so they can communicate. Imagine two computers in the same room sending messages back and forth. Now, imagine millions of computers across the globe connected—that’s the internet! 🌎💻

The internet allows computers worldwide to share information, stream videos, send emails, and much more. 🌐

Computers exchange bits of data, but for them to understand these bits, they follow certain rules. These rules are called network protocols.

A protocol is like a language that computers use to communicate. Just like humans follow rules in conversations, computers follow protocols to ensure they "speak" correctly.

Here are a few common protocols:

• HTTP: For browsing web pages. 🌐
• SMTP: For sending emails. 📧
• FTP: For sharing files. 📁

When you visit a website, your browser talks to a server using HTTP to request web pages. Here's how the process works:

1. Request: Your browser sends a message to the server asking for a specific resource (like a web page or image).

   • Example: GET /index.html HTTP/1.1
   • This means the browser is asking for the file index.html using HTTP version 1.1.

2. Response: The server sends back the requested page, and your browser displays it.

📝 Key Point:

• HTTP is the protocol that allows your browser to retrieve web pages.

Data like web pages, images, and videos are delivered using the Transmission Control Protocol (TCP). Think of TCP as the postman delivering your data securely! 📬

1. Client and Server:

   • The client is your browser requesting the data.
   • The server is the computer that holds the data, like web pages, videos, or images.

2. Connections:

   • Your browser connects to the server using an IP address (which identifies the server) and a port number (which specifies the service, like HTTP on port 80) and HTTPs on port 443 for secure connections.

     • IP Address 🏠: This is like the home address of the website. It tells your browser where to go on the internet to find the server hosting the site.

     • Port Number 🚪: Think of this as the door your browser knocks on when it reaches the server. Different services have different doors! For example:

     • 🌐 Port 80 is used for regular websites (HTTP).

     • 🔒 Port 443 is for secure websites (HTTPS).

3. Two-Way Communication:

   • The client and server exchange data (bits) through this connection. This ensures the data arrives correctly and in order.

The World Wide Web is not the same as the internet! The internet is the massive network connecting computers, while the web is a collection of web pages and the protocols that allow you to browse them.

1. URL (Uniform Resource Locator):

   • A URL is the address that locates a resource on the web. For example: https://www.google.com/
     • https:// is the protocol (how your browser should communicate).
     • google.com is the server address (where the data is stored).
     • /page.html is the specific page your browser is asking for.

2. Domain Names and IP Addresses:

   • Every machine on the internet has a unique IP address (like 192.168.1.1), which helps identify it.
   • Instead of remembering numbers, we use domain names (like google.com) to make it easier to access websites.

1. URL: When you type a URL (like https://www.google.com/) in your browser, it first finds the IP address of that domain using DNS (Domain Name System).
2. Request: Your browser connects to that IP address using HTTP and requests the web page.
3. Response: The server sends the requested page back to your browser.
4. Display: Your browser displays the page for you to view.

• JavaScript and Browsers: JavaScript became popular because of its ability to make web pages interactive.
• Internet and Networks: The internet is a global network that connects devices and allows data sharing.
• The Web: The web is the system that lets us browse resources (like web pages) through URLs, using HTTP to request them.