What is the internet, and what does it do?
The internet is a computer network. It is comprised of millions of individual computers all over the world that are connected by cable, fibre, wireless or satellite links. It has revolutionised how people communicate and work. Individuals can communicate via emails, social media, video, and audio. It also supports access to information digitally via the ‘World Wide Web’ – the leading information retrieval service on the Internet. Information is stored on web pages, and these web pages are collected together to form websites.
How does the internet work?
To understand how the internet works, we first need to know what a server is. Simply, a server is a special computer that is connected to the internet. They contain webpages and files on their hard drives. Each server has its own Internet Protocol address (otherwise known as an IP address), which acts like a postal address that allows other computers to find each other. Since IP addresses are an easily forgettable numerical label, they are given names like ‘bbc.co.uk’ or ‘facebook.com’.
Now that we know what a server is, we can start to break down how the internet works. Your computer at home is known as a ‘client’. It differs from a server because it isn’t connected directly to the internet. Instead, they connect to the internet indirectly through an ISP, otherwise known as an Internet Service Provider. Examples of ISPs in the UK are BT, Sky Broadband, Virgin Media, and TalkTalk.
- How does visiting a webpage work?
Let’s say you want to read the day’s news from the BBC on your computer from home, and TalkTalk provides your internet. You go onto your computer and go through your ISP and visit bbc.co.uk/news. The computer connects with bbc.co.uk/news and you can view its web pages.
- How is an email sent?
Let’s say that you have a Gmail account, and you want to send your best friend an email to their BT Mail account. Again, you go onto your computer, visit mail.google.com on your laptop through your ISP. You compose a message, enter your friend’s BT mail address, and click ‘send’. Gmail will then send the email to bt.com. When your friend signs into the BT servers, they will retrieve the email.
- How do emails, images, and web pages travel across the internet?
Whenever an email, image, or webpage travel across the internet, computers break them into smaller pieces called ‘packets’. When the information reaches its destination, these ‘packets’ are reassembled in their original order.
- How do different computers browse the internet on the same server and how do you receive the correct information?
Imagine that you are at work. Your boss is on the internet collecting market information from mintel.com, and you are tweeting about how bored you are on twitter.com. You are both sending ‘packets’ back and forth over the internet, but what is stopping your ‘packets’ from ending up on your boss’ screen? This would not be ideal – you would get caught by your boss tweeting about him! The solutions to this problem are IP addresses and routers. Everything that connects to the internet, directly or indirectly, has an IP address. Anywhere where two or more parts of the internet intersect, there is a piece of equipment called a ‘router’. Their job is to direct your ‘packets’ around the internet to their intended destination, one step at a time.
Let’s say your computer sends a ‘packet’ to the first router which adds its IP address. Each time a ‘packet’ reaches a new router, another IP address is added until it reaches the server. When the server then sends back information, it creates ‘packets’ with an identical collection of IP addresses to the ‘packet’ that was originally sent out by your computer, but this time it removes the IP addresses associated with each router it passes, eventually returning to your computer.
Frequently Asked Questions
What is a web browser?
A web browser is a software application that allows you to access the ‘World Wide Web’. You can ‘browse’ web pages from any website – this happens when the browser retrieves the desired content from the corresponding web server.
What is the homepage?
A homepage is the introductory webpage of a website, which normally acts as a table of contents. This will help you navigate around a website to get the web page you are searching for.
What is a URL?
URL stands for Uniform Resource Locators. A URL is a unique address given to a website. Entering a URL into the search bar of your browser will take you to a website.
What is a firewall?
A firewall is a security device that monitors incoming and outgoing network traffic. It will decide to block traffic based on a defined set of security rules.
What is the ‘dark web’?
The internet is massive. Web browsers are able to access billions of websites, and search engines display hundreds of billions of web pages in their results. However, they don’t even scratch the surface of the total web.
The results available on a web browser are known as the ‘surface web’. Under this surface level is the ‘deep web’ – these pages don’t appear on your search result index. Among these unindexed pages is the ‘dark web’, whose addresses are hidden from view. A special web browser is needed to access these sites. While the ‘dark web’ has legitimate uses, such as hiding the identity of ‘whistle blowers’, it also homes plenty of criminal activity.