Author: Brady Gavin / Source: How-To Geek
When you type an address into your web browser, a lot of things happen behind the scenes. And most of that is determined by the various parts of the URL you typed. Let’s take a closer look.
A URL can consist of a bunch of different parts. There’s a hostname that maps to an IP address of a specific resource on the internet and bunch of additional information that tells your browser and the server how to handle things.
You can think of an IP address as being something like a phone number. A hostname is like the name of a person whose phone number you want to look up. And a standard called the Domain Name System (DNS) works in the background like a phone book, translating the more human-friendly hostnames into the IP addresses that networks use to route traffic.Keeping that analogy in mind, let’s take a look at the structure of a URL and how it works to get you where you want to go.
How a URL Is Structured
The structure of a URL was first defined by Sir Tim Berners-Lee—the guy who created the Web and the first web browser—in 1994. URLs essentially combine the idea of domain names with the idea of using a file path to identify a specific folder and file structure. So, it’s similar to using a path like C:\Documents\Personal\myfile.txt in Windows, but with some extra stuff at the beginning to help find the right server on the internet where that path exists and the protocol used to access the information.
A URL consists of several different parts. Take, for example, a basic URL like the one shown in the image below.
That simple URL is broken down into two major components: the scheme and the authority.
Scheme
A lot of people think of a URL as just a web address, but it’s not quite that simple. A web address is a URL, but all URLs are not web addresses. Other services you can access on the internet—like FTP—or even locally—like MAILTO—are also URLs. The scheme portion of a URL (those letters followed by a colon) denote the protocol with which an app (like your web browser) and the server should communicate.
Web addresses are the most common URL, but there are others. So, you might see schemes like:
- HyperText Transfer Protocol (HTTP): This is the underlying protocol of the web and determines what actions web servers and browsers should take in response to certain commands.
- HTTP Secure (HTTPS): This is a form of HTTP that works over a secure, encrypted layer for safer transport of information.
- File Transfer Protocol (FTP): This protocol is often still used for transferring files over the internet.
In modern browsers, the scheme isn’t technically required as part of the URL. If you enter a website like “www.howtogeek.com”, your browser will automatically determine the right protocol to use. Still, some other apps (and protocols) require the use of a scheme.
Authority
The authority portion of a URL (which is preceded by two slashes) is itself broken down into a bunch of parts. Let’s start off with a very simple URL—the kind that would take you to the home page of a website.
In this simple example, the whole “www.example.com” part is called a hostname, and it resolves to an IP address. You can also type an IP address into your browser’s address bar instead of the hostname if you happen to know it.
But, when parsing the hostname it helps to read it backward to understand what’s going on, so here are those components:
- Top-Level Domain: In the example here, “com” is the top-level domain. These are the highest level in the Domain Name System (DNS) hierarchy…
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