How the Web Works – IB Computer Science

What is the primary job of DNS?

• Encrypt website data

• Improve download speed

• Convert domain names into IP addresses

• Manage browser settings

Answer explanation

The primary job of DNS (Domain Name System) is to convert domain names into IP addresses, allowing browsers to locate and access websites. This is essential for internet navigation.

A DNS server translates human-readable domain names into machine-readable IP addresses.

• True

• False

Answer explanation

True. A DNS server's primary function is to convert human-readable domain names, like www.example.com, into machine-readable IP addresses, enabling browsers to locate and access websites.

What is the first step your browser takes when you type in a URL?

• Loads the homepage

• Sends a request to the DNS resolver

• Renders JavaScript

• Opens Developer Tools

Answer explanation

When you type a URL, the first step your browser takes is to send a request to the DNS resolver to translate the domain name into an IP address, enabling it to locate the server hosting the website.

Which of the following is responsible for reliable delivery of data over the internet?

• IP

• TCP

• HTML

• CSS

Answer explanation

TCP (Transmission Control Protocol) ensures reliable delivery of data over the internet by establishing a connection and managing data transmission, while IP (Internet Protocol) handles addressing and routing.

Which protocol is best for transferring large files between computers?

• TCP

• FTP

• HTTP

• DNS

Answer explanation

FTP (File Transfer Protocol) is specifically designed for transferring large files between computers, offering features like resume capability and efficient data transfer, making it the best choice compared to TCP, HTTP, and DNS.

The Internet Protocol (IP) guarantees the data packets will arrive in order.

• True

• False

Answer explanation

The Internet Protocol (IP) does not guarantee that data packets will arrive in order. Packets can take different paths to their destination, leading to potential reordering. Therefore, the correct answer is False.

What is an IP address?

• A security feature

• A numerical address used to identify a device on the internet

• A browser extension

• A type of webpage

Answer explanation

An IP address is a numerical address used to identify a device on the internet, allowing it to communicate with other devices. This makes it essential for data transmission and connectivity.

What are common tasks performed by a web browser? (Select all that apply)

• Renders HTML, CSS, and JavaScript

• Sends HTTP requests to web servers

• Displays multimedia and forms

• Hosts websites

Answer explanation

Web browsers render HTML, CSS, and JavaScript to display web pages, send HTTP requests to fetch resources from servers, and can display multimedia and forms. However, they do not host websites.

Which browser function allows you to view all network requests during a page load?

• JavaScript console

• Network tab in Developer Tools

• Extensions tab

• History tab

Answer explanation

The Network tab in Developer Tools allows you to monitor all network requests made during a page load, providing insights into resources like images, scripts, and API calls. This is essential for debugging and performance analysis.

A browser uses DNS to resolve a domain name only if the address is not already cached.

• True

• False

Answer explanation

True. A browser checks its cache for a domain name before using DNS to resolve it. If the address is cached, it retrieves it from there instead of querying DNS, confirming the statement is correct.