How Does the Internet Work?

The goal of this article is to present the way the Internet works in a simple manner. We will take a look at the basic elements of the Internet, such as browsers, email, domains, IP addresses, internet connections and so on. The article is a loose follow-up of the previous part “How Was the Internet Created”, and we will use a bit less technical expressions and abbreviations.

The series about Internet:

Basic Internet usage

In order to better understand the way the Internet works, we need to take a look at its basic functions:

  • Data transfer – websites, downloading, sending emails, online calls, chatting and other things
  • Interconnection – of networks, computers, companies and so on

In other words, thanks to the connections between computers and servers, we can transfer data between those devices over the Internet, which makes up most of the Internet activity that you can think of. For example:

  • Websites – data transfer from a server to your computer’s Internet browser
  • Email – sending an email from your computer to the mail server to be downloaded to the recipient’s computer

Where are websites located?

www_internetWebsites are located on servers (servers are pretty much highly efficient computers) that make up the “backbone of the Internet” in so-called data centres. In order for you to get to Internet websites, you need to have a special program installed on your computer, an “Internet browser”, the best known being Chrome, Firefox, Safari and Internet Explorer. After opening your browser, you type in the address bar the domain name of the website that you want to visit, and after you click on the Enter button, the browser will find a way to the datacentre, or more specifically the server, where the website is stored.
If you enter “google.com” in your browser, it will ask the DNS servers what the IP address of the domain google.com is, and a DNS server will respond that the IP address is 172.217.0.46. Afterwards, the browser will download the google.com website’s data.

Why is the IP address hidden behind a domain?

Since the Internet is rather extensive, there was a need to assign a unique identifier. The identifier is an IP address consisting of twelve numbers (e.g. 112.113.114.155). But since remembering complicated number combinations is fairly difficult, domains that are much easier to remember were invented. Each domain redirects you to a specific IP address.

This redirection from a domain to an IP address is done by a “DNS”, a service that’s a part of your Internet connection. This server is operated by an Internet company. However, you can change your DNS default server settings, for example to Google DNS or Open DNS.

How does mailing work?

Mailing and emails form an integral part of the Internet, so we will take a look on how it works on the Internet. First, we will explain the difference between a computer mailing program and an online email client.

  • Computer (or mobile) mailing program – such as Outlook or Thunderbird. You can also find similar mobile apps. The application or program will automatically download and send mail between your computer and the mail server. A SMTP protocol is used in order to send an email, while a POP3 or IMAP protocol is used to download the email.
  • Mail server web interface – an online mail server interface. If you are using Gmail and you login directly to gmail.com, then you login directly to the mail server.

How does the email get from you to the recipient (PC to PC)?

  1. Write an email and click Send. The email client on your computer will send your email to the mail server.
  2. Your mail server will find out the address of the recipient’s mail server thanks to the second part of his email name, the part after the “at” symbol (@), for example “gmail.com”. Then it will ask the DNS records about gmail.com domain mail server’s IP address. The address of the mail server is called the MX record and it is different from the webpage address.
  3. The recipient’s mail server will send the email to a specific mailbox after receiving the message.
  4. The program on the recipient’s computer will download the email from the mail server.

How to connect to the Internet

internet_how_to-2In order to use the Internet, we first need to connect to it. In other words, we ask the Internet provider to connect us to the Internet. The Internet connection in your home is usually provided by either a router (a black box, roughly the size of a book) connected via cable to your computer or by a home wireless network (“Wi-Fi”).

Connection technologies

When you are dealing with an Internet connection, you can find several different technologies used for Internet access. Below, you will find listed technologies suitable for households and small companies, with lower prices at the cost of slightly worse performance.

  • ADSL/VDSL – internet access via telephone lines of telecom company. The speed depends on the distance from telephone exchange. The maximum speed usually is 40/2Mbps.
  • Cable TV – This type of internet access is used by owners of cable TV’s, and it is a high quality data network, offering more than 100Mbps. Unfortunately, not every house is connected via this network.
  • Home optics (FTTH) – This is the newest technology, available usually to modern housing estates. An optic network can connect you extremely quickly.
  • Wireless connection – A number of Internet providers offer access via a free zone wireless network. It is an interesting and rather cheap solution, suitable for places without any other alternatives.
  • LTE Mobile internet – Even mobile operators are offering Internet access via new LTE technology. LTE offers an Internet connection with a speed, depending on the signal in a particular location, up to dozens of Mbps. This connection, however, is one of the few that are limited by the amount of transferred data. The big advantage is that the connection is not, unlike others, tied to a particular place.

Apart from those technologies, there are other ways of connecting to the Internet, usually used by bigger companies or the government sector. These kinds of Internet access are better functioning, much more expensive and with much better service level agreement (SLA). Such Internet connections use technologies such as SHDSL, licensed radio, optic networks, satellite connections, laser and others.

Bits vs bytes – how to read online data

You must have already encountered the terms bits (b) and bytes (B). Bits (as in 10 Mbps or million bits per second) define the speed of the Internet connection, while bytes define the size of the file or amount of free space on your computer’s drive.

Bits vs Bytes

  • Bits (lowercase b) define the speed of the Internet
  • Bytes (uppercase B) define the size of your data
  • 8 bits = 1 byte – If the speed of your Internet connection is 10 Mbps, your download speed is 1.25MB/s. With a full-speed download, you can download a 700 MB movie in 9.3 minutes.

IP Addresses

IP addresses work as the Internet version of postal addresses in the real world. There are static public IP addresses, permanently assigned to a specific Internet connection, kind of like a house number. And just as you need to lock the front door of your house, you need to have a firewall, protecting you from potential breach risks. However, most household Internet connections have dynamic public IPs, meaning that your IP address can be different each time you sign in. You still need a firewall though, since the address remains the same for a period of few days. However, most of the time, it doesn’t really matter if you have a static or dynamic IP address, as long as you are an average Internet user. You would need a static IP address if you, for example, wanted to access your home IP camera from your work computer.
The aforementioned static and dynamic IP addresses for internet connection are both public IP addresses. Public and non-routable addresses differ. Non-routable addresses are usually used by companies, and they only work at a specific location. However, when browsing the Internet, you will always only deal with public IP addresses.
IPv4 and IPv6 addresses also differ. IPv4 addresses consist of twelve numbers (such as the aforementioned IPv4 172.217.0.46.) and are the most commonly used IP addresses. But due to the limited number of IPv4 addresses, the IPv6 address was created, consisting of a combination of numbers and letters. ADSL has been assigning IPv6 addresses since 2012.

Protocols

Protocols are officially approved ways of handling Internet communication. We will take a look at the few of the most commonly used ones:

  • HTTP – website browsing protocol
  • FTP – server file uploading protocol
  • SMTP – mail sending protocol
  • IMAP/POP3 – mail downloading protocol
  • SIP – online call protocols

Encryption

With the Internet becoming more and more popular, the number of attempted data thefts has risen dramatically. That was the main reason to implement encryption methods into internet communication in order to “lock it down”. Because of that, protocols have also encrypted versions:

 

Not encrypted Encrypted
HTTP HTTPS
FTP SFTP / FTPeS
SMTP SMTPs
POP3/IMAP POP3s / IMAPs

Who governs the Internet?

At least to a certain extent, the Internet works independently. However, there are a few organisations that influence it and provide it with some kinds of direction in certain ways. I’d like to point out three main factors:

  • defining and approving of protocols,
  • assigning IP addresses and domain names and
  • Internet content check provided by governments on a state level.

Internet Society (ISOC) – This is an international non-profit organisation aimed at setting the standards used on the Internet, education and specific methods. One of its main goals is “ensuring an open development and spreading of the Internet for all of the humanity around the globe”.
Internet Corporation for Assigned Names and Numbers (ICANN) – This is a non-profit organisation which takes care of the assignment and registration of domain names and IP addresses on a global level. ICANN takes care of generic domain registration and is the central umbrella organisation for the regional organisations providing registration services on different continents (ARIN, APNIC, LACNIC, RIPE, NCC).

Who influences the Internet locally

Both of those aforementioned institutions are international organisations, with ISOC taking care of Internet protocols and standards and ICANN handling IP addresses and domain assignment. However, there are at local companies possessing a certain amount of influence on the local Internet as well.

  • Internet exchange – a peer-to-peer center. It is a space in the data center where all the internet providers
  • Domain name registrars – The core of its activities lies in hosting the “.tld” domain names and ensuring the domain’s safe operation.
  • Site search companies – a company operating the search engine. They also runs several other online activities

 

Don’t forget to take our free “Internet knowledge” test at: “The Internet Knowledge Test”.

Radek Kucera

Work as a salesman in ICT/Telco branch more than ten years, WordPress fan and blogger. Interested to write about an Internet and ICT topic.

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