Lucid Tech Talk: Understanding IP Addresses
What’s an IP address?
We use the Internet every day for everything. It’s become such an integral part of our lives that we don’t even think about how often we use it – it’s like flipping on a light switch or opening the refrigerator. We only notice it when it’s not there . . . at which point we panic and start wondering “do I own a phone book?” and “how do I use a phone book?”
For something that we rely on so heavily, it’s incredible how many of us don’t know how it actually works. I mean, we understand that typing “youtube.com” into our browser will deliver us hours of cute cat videos – but most people have no idea what actually goes into translating a human request (youtube.com) into something the computer understands.
What’s in a name?
The first thing I always explain when I’m trying to demystify the Internet is the difference between an Internet host and a domain registrar. This is confusing to many people because companies like GoDaddy provide both services. A domain registrar sells domains. They’re like an auction house. Domains are simply names. It’s the Internet equivalent of “Bob” or “Jim” or “Mary” – it’s just a name. The difference between humans and websites, of course, is that there can be a million Bobs and Jims and Marys, but domain registrars may only sell a name ONCE. Once it has been sold, it’s gone, and no one else may buy it. Most people understand this already. It’s common sense – it’s why fun.com would probably cost you an obscene amount of money, but you could buy fun7632hello.com for $9.50.
So that’s it – domain registrars will sell you a name, and just a name.
The files are IN the computer
Hosting is a completely separate service. An Internet host is a company that sells you space on a server to store the files that make up your website. Some popular hosting services are:
When you pay for hosting, you’re paying for the space on the server (servers are physical computers) to store your site files. These major companies typically offer two kinds of hosting
- Dedicated hosting
- Shared hosting
The cheaper option is shared hosting. This means that your website files are on the same physical server as about 20-30 other websites. Each website on the shared server has its own virtual server. All of these virtual servers are living together on the same physical computer. For a bit more money, you can purchase dedicated hosting. This means that your files live on a server, alone.
Finding the files
Each server (whether a shared server or a dedicated server) has an IP address. The IP address is basically the server’s identification number. All servers have a unique IP address. In fact, all devices that connect to the Internet have a unique IP address – your computer has an IP address, your mobile phone, your office server – everything! IP stands for “Internet Protocol”.
The IP address identifies 2 main things about the device or server:
- Host or network
There are 4,294,967,296 possible IP addresses, and each and every device that connects to the Internet must have a unique IP.
Because each device has a unique IP address, you could open your Internet browser, and enter an IP address to access a website. For example, you could type in 184.108.40.206 to access weather.com. When you type in 220.127.116.11 you’re telling your browser to access the files that live on the server with that IP.
Of course, it would be impossible (and annoying!) for us to remember IP addresses for all the websites we visit on a daily basis. That’s where DNS records come in. DNS records define where “domains” (remember, domains are just names like weather.com) should “point.” So, weather.com’s DNS host defines that the domain name “weather.com” should point to the IP address 18.104.22.168. When a user types “weather.com” into a browser, the browser is instructed to load the appropriate files that live on the server with the IP address 22.214.171.124
But what about shared servers?
Go ahead, type 126.96.36.199 into your browser. It works doesn’t it? Told ya! Now try this other, totally valid IP address: 188.8.131.52
When you enter that into a browser, you’ll get some sort of generic message, and no website– but why?
This is because the server with this IP address is a shared server. Remember, several websites live together (on virtual servers) on one single shared server. Your browser has no idea which of those 20-30 sites you’re trying to visit when you type in 184.108.40.206 because you could be referring to any of the sites that live on that physical server.
For websites on a shared server, you must use the domain name to access the website. When you type a domain name into your browser, the DNS record for that domain name returns the correct IP address for the physical server. In this example, it would return 220.127.116.11. Then, the virtual host file on that physical server “hears” the domain name that you specified, and directs you to the appropriate site on the server. It works something like this:
Let’s wrap it up
Essentially, an IP address is a numeric code or label that is assigned to every device that connects to the Internet. The IP address gives information about that device’s host or network and that device’s location. Every server that hosts a website has a unique IP address. In the case of servers that host website files, a server may be either dedicated or shared. If the server is dedicated, accessing the site via the IP address, only, will be successful. If the server is shared, you must use the domain name to access the site.