Web - URL

An Uniform Resource Locator (URL) is a universal identifier for a resource.

It's the string that is understood by a browser when you put it in the address bar.

When the HTTP protocol is used as scheme, it's a identifier for a Web resource.

An URL was originally created to provide a method for finding an item such as a person's street address.

On a format level, the URL is a subset of an URI.

scheme://[[email protected]]host[:port]/path?query#fragment

where:

• scheme is the scheme and defines the access protocol that can be:
  • http or https defines the HTTP protocol (and we will make HTTP request)
  • file defines the local file system (and will make call to the local OS)
• user-info is optional and defines the credential (not used with the file scheme)
• host[:port]] defines the endpoint (not used with the file scheme)
• path is the path to the resource
• query is the query string
• fragment is the fragment that identify a part in the resource.

See URL - URL Rewrite

See URL - URL encoding (Percent-encoding)

Lowest common denominator max URL length among popular web browsers is 2100 (Reference)

You can create unique same-length identifier with the version 3 and 5 of UUID and the url namespace.

See Browser URL

• W3C URL specification
• The W3C URL specification defines the term URL, various algorithms for dealing with URLs, and an API for constructing, parsing, and resolving URLs.
• HTML5 URL parsing