A game engine is a framework for game development that supports and brings together several core areas. You can import art and assets, 2D and 3D, from other software, such as Maya or 3s Max or Photoshop; assemble those assets into scenes and environments; add lighting, audio, special effects, physics and animation, interactivity, and gameplay logic; and edit, debug and optimize the content for your target platforms.
Unity is a cross-platform game engine developed by Unity Technologies, first announced and released in June 2005 at Apple Inc.’s Worldwide Developers Conference as a Mac OS X-exclusive game engine. As of 2018, the engine had been extended to support more than 25 platforms.
Modern game engines can power stunning graphics and help facilitate the production, as well as the importing of assets from different platforms, so that you don’t have to wait a lot of time with every import.
For most games, game engines can provide you with an architecture with overall high performance rendering capabilities, and with access to fast graphics API, so you can enable the greatest visual fidelity for your games.