Final Fantasy VII is a video game RPG developed by Squaresoft (now Square Enix), originally released for PlayStation 1 and subsequently made available on PC; PS Store for PSP, PS3 and PS Vita (N.B. PS Store is no longer available on PSP); Steam; iOS; Android; PS Store for PS4; and from 2019, for Nintendo Switch and Xbox One. A PlayStation 1 Disc can also be used with a PS2 or PS3; and the game is also included with the PlayStation Classic.
I recommend playing the game, if possible, on PlayStation 4 or as the Steam PC download. Not only do these feature Trophies/Achievements, but they are better optimized in terms of graphics and features than other versions. Playing on PC has the added benefit that you can take advantage of mods. The upcoming Nintendo Switch and Xbox One releases should also be on a par with the PS4 version.
Final Fantasy VII is a huge commercial success, selling over 11 million copies and counting. It is regarded by many, including myself, as the best RPG and best video game ever made.
Final Fantasy VII is the story of how Cloud Strife, a mercenary in the slums, becomes aware of threats to the Planet's future and confronts those threats, meeting a number of zany friends and foes along the way. The game features cross-dressing; submarines and space rockets alongside swords, magic and dragons; as well as an anti-hero in the form of Cloud who is always up for some fun even if he's not too sure what's going on, and Sephiroth, an anti-villain you can almost sympathize with at times despite him being hell-bent on destroying the Planet.
Note that although Final Fantasy VII is the 7th game in the Final Fantasy series, the games all feature self-contained storylines with only certain themes carrying over between games.