Encode or decode URL components and query strings.
Percent-encode text for safe use in a URL, or decode an already-encoded URL back to readable text.
Component mode (encodeURIComponent) escapes reserved characters like & and = for use inside a query parameter; full URL mode (encodeURI) leaves URL structure characters intact.
Component mode escapes every reserved character, which is correct for a single query parameter value. Full URL mode leaves characters like :/?& untouched, since they're structurally meaningful in a complete URL.