A Uniform Resource Locator (URL) is the address of a web resource. It helps browsers and applications find web pages, files, and APIs. URLs were introduced as part of the World Wide Web by Tim Berners-Lee. They are a subset of URIs (Uniform Resource Identifiers).
In simple terms, a URL tells your browser where something is and how to access it.
https://rohit:pass@www.rohitshukla.net:8080/path/to/resource?query=example&sort=asc#fragmentAt first glance, this might look complicated, but each part has a specific purpose.
Components of a URL
A URL can have up to nine distinct components, though not all are required in every case. These are:
- Scheme (Protocol)
- User Information (Username and Password)
- Host (Domain or IP Address)
- Port
- Path
- Query String (Parameters)
- Fragment
- Authority (Combination of User Info, Host, and Port)
- Delimiter (Separators like ://, @, :, /, ?, #)
1. Scheme (Protocol)
The scheme specifies the protocol used to access the resource. It is the first part of a URL and is followed by ://. It tells the browser how to communicate with the server.
Examples:
- http (HyperText Transfer Protocol)
- https (HTTP Secure, encrypted with SSL/TLS)
- ftp (File Transfer Protocol)
- mailto (Email)
2. User Information
User credentials (username and password) can be embedded in a URL, separated by a colon (:) and followed by @.
Example:
https://rohit:pass@www.rohitshukla.netThis method is rarely used in modern web URLs due to security risks. Most browsers ignore this part, but it is still common in FTP and certain API calls.
3. Host
The host identifies the server hosting the resource. It is usually a domain name but can also be an IP address.
Examples:
- Domain: www.rohitshukla.net
- IP: 192.168.1.1
A web address is always linked to an IP address, which is translated by DNS (Domain Name System). Computers understand IP addresses, not domain names.
- www is a subdomain of rohitshukla.net.
- .net is a Top-Level Domain (TLD).
Each TLD has a specific purpose. some examples are:
- .com – Commercial sites
- .net – Networking or technology
- .gov – Government entities
- .edu – Educational institutions
- .in – India
- .ca – Canada
4. Port
A port is a number that specifies the communication endpoint on the host. It follows the host and is preceded by a colon (:).
Examples:
- :80 (Default for HTTP)
- :443 (Default for HTTPS)
- :8080 (Common for development servers)
5. Path
The path specifies the location of a resource on the server. It works like a file path on a computer and starts with a forward slash (/).
Examples:
- /blog
- /users/profile/settings
6. Query String
A query string provides additional data to the server. It starts with a question mark (?) and separates key-value pairs with ampersands (&).
This is commonly used in APIs and dynamic web pages for filtering, searching, or customizing responses.
Examples:
- ?search=cat&page=2
- ?id=123&sort=asc
7. Fragment
A fragment identifies a specific section within a page. It starts with a hash (#) and helps direct the browser to a particular part of the content. Fragments are optional and often used in single-page applications.
Examples:
- #section1
- #top
- header
8. Authority
The authority part includes user info, host, and port. It appears between the scheme and path. The @ separates user info from the host, and : separates host from port.
Example: rohit:pass@www.rohitshukla.net:8080
9. Delimiters
Delimiters are special characters that separate URL components.
Examples: //, @ , : , / , ? , #
Conclusion
From the scheme to the fragment, every component of a URL plays a critical role in locating and accessing resources. Whether you’re a casual user, a developer, or a curious tech enthusiast, understanding URLs empowers you to navigate and build the web more effectively.