Did the first Xbox 360 in 2005 support HD?

Over the years, new and improved models of the Xbox 360 came out, but the original console was released in 2005. I would like to know if this first version already supported HD, as HD was hardly used in 2005. The Ps3, published in 2006 or 2007, initially failed because the technical innovations made the console quite expensive, but the Xbox 360 is said to have been significantly cheaper than the Ps3 and was more successful for a long time. Does anyone know if the first Xbox 360 already supported HD? I didn't find anything about it on the internet…

HD for sure. But I don't know FullHD

No, the first generation of the 360 only had a scart connection