What is URL (Uniform Resource Locator)?

May 16, 2023 - (Free)

A Uniform Resource Locator (URL) is a standard internet address for finding a particular resource, like a file or an application. Users can recognize it as the text string that appears in the browser address bar of each online page or that directs them to another internet location. A Uniform Resource Identifier (URI) is a type of URL.


History of URL

Finding a way to allow information sharing on computers was where it all started. The path leading to the introduction of URLs is highlighted by three instances:

  • The first node-to-node transmission over the Advanced Research Projects Agency Network (ARPANET) was made in 1969 utilizing the ARPANET 1822 Protocol between UCLA and the Stanford Research Institute. A Transport layer was created in 1970 with the Network Control Protocol (NCP), which consists of the Physical, Data, and Network layers.
  • In 1983, the ARPANET moved from NCP to TCP/IP (Transmission Control Protocol/Internet Protocol).
  • The World Wide Web (WWW), which Tim Berners-Lee founded in 1989 and which also featured resource identifiers, protocols for resource retrieval, and the markup language, were all innovations.

Data transmissions were stabilizing when Berners-Lee presented the WWW to the globe. By the early 1990s, the internet had matured sufficiently to deliver files, mail, and data via protocols like Gopher, FTP, and Telnet.

In 1992, the moment was right for Berners-Lee to define the URL as a tool for linking to the location of any internet resource a user might require. Despite the fact that his focus on URLs was for the web and its HTTP protocol, his vision included most internet protocols.

Components of a URL

The protocol, domain, path, and query are the four fundamental components of URLs.

Let’s take a deeper look at the various URL components with the following example:



The protocol or scheme of a URL specifies the technique for transmitting or exchanging data. For the transfer of HTML files, the most used system is the Hypertext Transfer Protocol (HTTP) or Hypertext Transfer Protocol Secure (HTTPS). Other types of systems include FTP (for files) and Mailto (for emails).

The secure protocol for the URL in the example URL above is https://.


A URL’s domain or hostname is a user-friendly expression of a website’s Internet Protocol (IP) address. It indicates the location of the host server for the website.

The domain in the preceding example is www.example.com.


Within a URL, the path that follows the domain name links to a specific file or other resource location. It may also contain a query string.

In our example URL, /category-A/subcategory-A1/model-123.html represents the URL route, which in this case leads to a product page.


The query string, also known as a fragment identifier, is typically used for internal searches and is frequently followed by a question mark (?).

For example:


This URL was generated when a user searched for “Model 123” on the subcategory A1 page. In this case, the landing page is either the model 123 product page or a list of search results that include the keyword “Model 123.”

Characters allowed in URLs

The World Wide Web Consortium defines the characters that can be used in URLs. There are lists of unreserved and reserved characters in the specifications.

  • Unreserved Characters: These are not reserved and can be used in URIs and URLs without restriction. All upper and lower case letters, all decimal numerals, hyphens and underscores, tildes, and periods are included.
  • Reserved Characters: Within a URI/URL, these provide certain functions. They are as follows: / ; 😕 @ &, + $ =.

Reserved characters are reserved characters that can only be used for delimiting or other special uses within a URL unless they are URL-encoded. This means that encoding is required to show a “?” as a question mark or a “+” as a plus sign within a URL string.

Examples of the usage of Reserved Characters inside a URL

  • The Forward Slash “/” is used to separate components of a URL, such as separating the file path from the domain.
  • The Question Mark “?” is used at the beginning of a query.
  • The Equal Sign “=” is used between the name of a parameter and the value assigned to that name.

Differences Between URL and Domain

Although a domain might simply a URL, such as a homepage, most URLs contain far more information than just the domain name. URLs are made up of resource addresses, file paths, and queries.

The domain name is a simple way to list an IP address that is easy to remember.

Components of a Domain

A domain is separated into three hierarchical tiers, which begin on the right side of a URL’s domain component.

  • Top-level Domain: .com, .net, .biz, or.de are examples of domain name extensions.
  • Mid-level Domain: the element that can be adjusted the most. It could be a word or the name of an organization. Another name for it is the second-level domain.
  • Prefix: the mid-level domain’s WWW prefix. Although it is not necessary, it was the first thing that set apart web URLs from other URL schemes.

Domain Extension

The part of a website name that comes after the dot is known as a top-level domain (TLD). The most common extension, .com, is used on about 53% of all websites.

The following TLD extensions are some to think about using:

  • Generic TLD (gTLD): The majority of well-known extensions, including
    • .com: Commercial websites”
    • .org: Nonprofit organizations”
    • .net: Software and hosting companies providing network services”
    • .edu: Educational institutions (universities, colleges, schools, etc.)”
    • .gov: Government agencies and departments” fall within this category
  • Country Code TLD (ccTLD): This TLD denotes a nation, a territory, or a geographic region, as its name suggests. ccTLDs are made up of two letters that are based on international country codes like
    • .uk for United Kingdom”
    • .de for Germany”
    • .cn for China”
    • .ca for Canada”
    • .in for India”
    • .es for Spain”
    • .au for Australia”
    • .nz for New Zealand”
  • Sponsored TLD (sTLD): Specific organizations use and sponsor this kind of extension. For instance, “.travel” is sponsored by Tralliance Registry Management Company, LLC, and “.asia” is sponsored by DotAsia Organization Ltd.
  • New gTLD (nTLD): It’s a new breed of domain extension. Any TLD launched after January 12, 2012, is considered a new gTLD, including “.online, .store, and .tech“.

Absolute vs Relative URLs

Links to other web pages can use relative URLs if the resources are on the same server as the referencing page if a website has several pages branching off from its home or category pages. Although relative URLs are easier to use than absolute URLs, if resources are regularly moved, the webmaster must take great care to prevent broken links. With the frequent usage of absolute URLs, it could be wiser to err on the side of caution.

A link points to a product in a subcategory on the website https://www.example.com/category-A/:

<a href="subcategory-A1/model-123.html">Model-123.html</a>.

This relative URL will send the user to the web page describing the product “Model 123” if all the product pages in subcategory-A1 are on the same server as the Category A page.

What Are the Different Types of URLs

The most common types of URLs are absolute and relative.

An absolute URL includes everything, from the protocol to the path to resources or parameters. A relative URL, on the other hand, merely includes the path to resources.

Here are several other uniform resource locators, listed according to their function:

  • Canonical URLs: They can be used by site owners if they have duplicate content. Setting a single URL as canonical tells search engines which internet address to crawl and index.
  • Callback URLs: When users complete a process on an external system, they refer to a home destination.
  • Vanity URLs: They are easy-to-remember web addresses, often known as custom short URLs. A vanity URL is typically a redirect of a lengthier URL. A vanity URL can be created by using a website URL shortener service such as Bitly, Short.io, or TinyURL.

Where Is a URL Located

A URL is often found in the address bar at the top of the web browser window. A website URL will always be visible in the address bar on laptops and desktop computers while users scroll around the web page.

When using a mobile device, the default browser behavior causes a URL to vanish as soon as the user begins scrolling down. It will, however, reappear as users scroll higher.

How to Open a URL

  • Clicking a Hyperlink: It could be text, an icon, or an image that directs the user to another HTML file on the internet. Hovering the mouse over the connected text or graphic identifies a hyperlink. Then, at the bottom of the window, a URL link will display, informing users of where the link will take them.
  • Scanning a QR Code: A QR code is a black and white barcode that can be read by digital devices. It holds several types of data, such as web URLs, account information, and encryption details.
  • Copying and Pasting: Copying and pasting a website address into the address bar will open it if it has no links or QR codes.

How to Create a URL

Locate a reliable registrar to register a domain name on your behalf if you want to build a distinctive URL, such as linux.org or microsoft.com.

An ICANN-accredited business that handles domain registrations and renewals is known as a registrar. Among the most well-known registrars are Google Domains, CloudFlare, and Domain.com.

What Is a URL FAQ

The most frequently asked questions concerning a unified resource locator (URL) are addressed in this section.

1. How Do I Find My URL?

A custom domain name can be obtained from a registrar or a hosting provider that provides registration services. In general, the procedure consists of the following steps:

1. Creating a unique name.
2. Running a name search.
3. Registering the chosen name.

2. How to Block a URL?

A URL can be blocked in four different ways:

  • Edit the Hosts File: To block a website, point its domain name at your localhost IP address.
  • Use a Google Chrome Extension: A site blocker extension, such as BlockSite, can be installed by Windows and Mac users.
  • Install a Site Blocker on iOS and Android: After installation, users can tap the green plus icon to add websites and apps to their block list.
  • Utilize built-in Parental Controls: To add a block list, parents on Windows 10 can create a kid account.