URL encoding represents certain characters in an address using an agreed encoded form so the address can be parsed and transmitted correctly. It is a text-representation mechanism rather than encryption. Encoded parameters can still carry private information, and decoding or changing them carelessly can alter the meaning of an account-related request sent to a service.
A practical example
A draft support link can encode spaces and punctuation inside its message parameter. A private playlist URL can likewise encode meaningful characters, so copying the complete issued address accurately is safer than trying to improve its appearance by removing those sequences.
A common misunderstanding
Encoded text is not automatically secret. Do not publish a URL merely because its account data looks unfamiliar, and avoid double-encoding an address if the receiving field expects the original issued form.
Related terms
Stable technical definition. Editorial approach