what are game engine

Answer 1

A software framework build to design and create games..

https://en.m.wikipedia.org/wiki/List_of_game_engines

Answer 2

A game engine is a software framework designed for the creation and development of video games. Developers use them to create games for consoles, mobile devices and personal computers. The core functionality typically provided by a game engine includes a rendering engine ("renderer") for 2D or 3Dgraphics, a physics engine or collision detection (and collision response), sound, scripting, animation, artificial intelligence, networking, streaming, memory management, threading, localization support, scene graph, and may include video support for cinematics. The process of game development is often economized, in large part, by reusing/adapting the same game engine to create different games,[1] or to make it easier to port games to multiple platforms.