Module 1.4 - What is a browser and how it works

Question 1

What is a browser?

Answer 1

A browser is a software application that allows users to access, retrieve, and display web pages and other web content on the Internet. Examples include Chrome, Firefox, Edge, Safari, and Brave.

Question 2

What is the role of a browser in accessing web pages?

Answer 2

What is the role of a browser in accessing web pages?
Answer: The browser contacts the web server that hosts the requested resource, sends the URL of the resource, receives the information back, and displays it. The browser starts with a DNS lookup to get the server IP address, which it uses to contact the web server and retrieve the content to display.

Question 3

What are URLs and what role do they play in the Web?

Answer 3

URLs, or Uniform Resource Locators, are addresses of resources on the Web. They are one of the core fundamental blocks of the Web and are used by browsers to access web pages and other web content.

Question 4

What happens when a URL is typed into a browser?

Answer 4

When a URL is typed into a browser and entered, the browser performs a series of steps to display the requested page. This includes looking up the URL, contacting the web server that hosts it, sending the URL of the resource requested, receiving the information back, and displaying it.

Question 5

What is the role of DNS in the process of loading a webpage in a browser?

Answer 5

The browser performs a DNS lookup to get the IP address of the server hosting the requested resource. This involves checking the local DNS cache, making a request to the DNS server, and, if needed, the root DNS server. The root DNS server returns the IP of the top-level domain (TLD) DNS server, which in turn has the IP addresses of the authoritative Name Servers for the domain being looked up. The ultimate source of truth for the IP address is the authoritative Name Server, which the browser uses to contact the server and receive the requested information.