URLaddress

URLaddress, often shortened to URL or web address, is a Uniform Resource Locator—a string that identifies a resource on the Internet and describes how to retrieve it. A URLaddress specifies both the location of the resource and the protocol used to access it, allowing a client such as a web browser to fetch the resource from a server.

A URLaddress is made of components: a scheme (or protocol) such as http or https, a host (domain name or IP address), an optional port, an optional path, and optional query and fragment identifiers. Example: https://www.example.com/path/to/resource?query=value#section. Some URLs may include user information before the host and a port number after the host. If the port is omitted, default ports are assumed (80 for http, 443 for https). Non-alphanumeric characters are usually encoded using percent-encoding to ensure safe transmission.

URLs are a specific form of URI; a URI can be a location, a name, or both. The formal syntax was first defined in RFC 1738 and later refined by RFC 3986. In practice, engines parse, normalize, and resolve URLs to access resources, and web infrastructure relies on them for routing and linking.

Use cases include absolute URLs that fully specify a location and relative URLs that resolve against a base URL in documents and APIs. Proper encoding, validation, and security considerations are important to avoid issues such as malformed URLs, phishing, or unintended redirects. URL shortening services, while convenient, can obscure destinations and introduce trust risks.

History: URL concepts emerged with the early World Wide Web; Tim Berners‑Lee and colleagues developed the initial design in the 1990s. RFC 1738 (1994) defined URLs and URNs; RFC 3986 (2005) established the current URI syntax.