Short answers, pulled from the story.
The PlayStation Vita was officially announced by Sony on the 27th of January 2011 at their PlayStation Meeting press conference held in Japan. The system was initially known by its code name Next Generation Portable and aimed to deliver PlayStation 3 quality visuals.
The original PlayStation Vita includes a quad-core ARM Cortex-A9 MPCore CPU, a quad-core SGX543MP GPU, 512 MB of system RAM, and 128 MB of VRAM. It features a 5-inch OLED touchscreen, dual analog sticks, front and shoulder buttons, two 0.3 megapixel cameras, stereo speakers, and a microphone.
The PlayStation Vita sold 1.2 million units as of the end of February 2012 and reached 4 million units by the end of 2012. Analysts estimated that sales reached 6 million units after two years of availability, though Sony ceased releasing direct sales figures after hitting the 4 million mark.
Sony announced on the 20th of September 2018 at Tokyo Game Show 2018 that the PlayStation Vita would be discontinued in 2019. Production of new physical games ceased by the end of Sony's 2018 fiscal year which ended on the 31st of March 2019, and hardware production officially ended on the 1st of March 2019.
The PlayStation Vita underperformed because it faced high retail prices, perceived lack of software variety, and strong competition from mobile gaming and the Nintendo Switch. Sony projected selling 16 million combined units for the Vita and PSP but had to slash forecasts twice down to 10 million units sold due to these market conditions.