Glossary · Internet & Web

URL (Uniform Resource Locator)

A URL is the full web address of a resource, combining a scheme, host, optional port, path, query string and fragment that tell a browser where to fetch it.

Updated October 6, 2026

A URL (Uniform Resource Locator) is the address that identifies where a resource lives on the internet and how to retrieve it. It is what you type in a browser's address bar or follow in a link.

Why it matters

Every request on the web starts with a URL. Browsers split it into parts to decide which protocol to use, which server to contact and which resource to ask for. Small details such as a trailing slash, upper-case letters in the path or a missing www can lead to different pages, duplicate content or redirect chains, so site owners need to read URLs precisely.

Example

https://www.example.com:443/blog/post?id=7&ref=news#comments
  • https is the scheme (protocol)
  • www.example.com is the host
  • :443 is the port (usually omitted)
  • /blog/post is the path
  • ?id=7&ref=news is the query string
  • #comments is the fragment

Common mistakes

  • Using spaces or non-ASCII characters without percent-encoding, which breaks links in some clients.
  • Treating example.com/page and example.com/page/ as the same URL; servers may not.
  • Changing URLs during a redesign without 301 redirects, which breaks bookmarks and search rankings.

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