Short answers, pulled from the story.
Dengeki PlayStation first went on sale in December 1994 as a special edition of Dengeki G's Magazine. It ceased print publication on the 28th of March 2020 with issue No. 686, after 26 years in print.
The publisher, ASCII Media Works, cited changes surrounding media such as magazines and changes in the delivery of game information. The magazine's content continues digitally through the Dengeki Online website.
Issue No. 686, the final print issue released on the 28th of March 2020, featured Cloud Strife from Final Fantasy VII Remake on its cover.
Four special editions were published under the Dengeki PlayStation umbrella: Dengeki PS2 (1997-2008), Dengeki PSP (2004-2011), Dengeki Girl's Style (launched 2003, later independent), and Dengeki Online D (2007). Each focused on a distinct platform or audience.
Dengeki Girl's Style began on the 4th of December 2003 as a special edition of Dengeki PlayStation under the name Dengeki PlayStation Girl's Style. It became an independent magazine in early 2007, dropping the PlayStation name, and began monthly publication on the 10th of April 2012. It covered otome and boy's love games, anime, and manga aimed at female audiences.
Dengeki PlayStation was published by ASCII Media Works, formerly known as MediaWorks. The magazine focused primarily on the PlayStation brand and its associated hardware throughout its 26-year run.