Short answers, pulled from the story.
Microsoft officially revealed the design and branding of the Xbox Series X during a presentation at The Game Awards 2019. This event also confirmed a late 2020 release date for the console family.
The Xbox Series X features a custom NVM Express SSD with 802 GB available space out of 1 TB total capacity. It delivers a raw input/output throughput of 2.4 GB/s which reaches up to 4.8 GB/s when using combined compression algorithms.
The Xbox Series X launched at $599 while the lower-cost Series S model launched at $299. Both consoles became available in stores on the 10th of November 2020 after being delayed from earlier plans due to production issues.
Engineers determined that meeting performance goals required parts drawing approximately 315 W of power which generated significant heat. Splitting the CPU, GPU, memory, and power regulators onto one board and the Southbridge functions onto another allowed for better cooling through air channels in the aluminum chassis.
Both the Xbox Series X and Series S consoles launched on the 10th of November 2020. This release date followed years of development rumors starting as early as June 2018 and official confirmation during E3 2019.