Short answers, pulled from the story.
The PlayStation Vita was first released in Japan on the 17th of December 2011, followed by North America and Europe on the 22nd of February 2012. Hardware production officially ended on the 1st of March 2019, after Sony announced the discontinuation at Tokyo Game Show 2018.
Sony never released official lifetime figures. Estimates place total sales at around 15 to 16 million units. Research firm EEDAR estimated approximately 10 million units sold through the end of 2015, while Glixel estimated around 15 million in mid-2017 and USGamer estimated roughly 16 million by September 2018.
Sony executives cited several factors: proprietary memory cards that were widely criticized as "incredibly expensive", a rear touchpad that added cost without broad game support, and the company's inability to fund both the Vita and the PlayStation 3 simultaneously while the PlayStation 4 was in development. Former vice president of marketing John Koller also believed the Vita launched too close to the PlayStation 4's release, diverting first-party developer attention away from the handheld.
The Vita features a custom system on chip with a quad-core ARM Cortex-A9 MPCore processor and a quad-core SGX543MP GPU. It includes 512 MB of system RAM and 128 MB of VRAM. Sony described its processing power as roughly halfway between the PSP and the PlayStation 3.
Sony's Director of Strategic Content, Shahid Ahmad, directly courted independent developers after major publishers like Ubisoft and Activision reduced their Vita support around 2012. Games including Fez, Spelunky, Hotline Miami, and OlliOlli found success on the platform. Ahmad also used social media engagement to influence localization decisions; Tales of Hearts R received an English release specifically because it topped a community survey.
The original model, released in 2011-2012, features a 5-inch OLED touchscreen. The revised PS Vita 2000, released in Japan on the 10th of October 2013, is 20% thinner and 15% lighter, adds 1 GB of internal storage, and includes approximately one extra hour of battery life, but replaces the OLED display with a lower-cost LCD panel.