Assuming you just entered the world of web development, while building projects you have likely seen the term "localhost" with the number "127.0.0.1:" while using a live server plugin.

You might be using it to test websites and web apps locally, without knowing exactly what it is. In this article, you will learn what localhost is alongside its corresponding IP address, "127.0.0.1".

What is Local Host?

In computer networking, host means a "server". Same as we host a website on a server on the internet. We make our computer that server. This connection is called loopback. The IP address for this loopback is 127.0.0.1.

The websites that you visit on the internet are hosted by companies like Vercel, Netlify, Heroku, and many more. These are what referred to as "remote hosts" or "virtual servers".

So when your surf on a website to test it without connecting to the internet, what you're dealing with is a localhost.

What is IP Address 127.0.0.1?

While visiting a website, you type the website address to your browser's address bar. The Domain Name Server (DNS) matches the address to a numeric IP address similar to that name.

Localhost is not an exception to this. So, if you type localhost to your browser's address bar, it transforms to the IP address 127.0.0.1. This address is reserved for local servers on computers, so you will never find another IP address that starts with 127.

But what's the similarity between the two?

Just like HTTP and HTTPS, the localhost is a protocol. Remember that the website domain name is what follows the http or https, for example, https://www.google.com/ or https://hashnode.com/.
So, something has to follow localhost: and 127.0.0.1:. That thing is the port number.

For example, while using the live server extension of VS Code, it uses a port 5500 attached to 127.0.0.1, followed by the filename:. Something like this:

Conclusion

Hope this article has helped you gain knowledge about localhost, what its IP address is, and how it works to serve websites for local testing.

And yes! There’s no place like localhost. Properly put, there’s no place like 127.0.0.1.

Keep learning & Keep building...