Is the HKD pegged to the USD?

Could you please clarify for me if the Hong Kong Dollar (HKD) is indeed pegged to the United States Dollar (USD)? I understand that the exchange rate between the two currencies is often stable, but I'm curious to know if there is an official arrangement or agreement in place that officially ties the value of the HKD to the USD. I'm interested in understanding the mechanics behind this potential peg, and how it affects the Hong Kong economy and financial system. Thank you for your time and consideration.