Once you’re done making your game, you might think the hard part is over, but unfortunately if you’ve never actually released a game before, you may be surprised by the number of steps still left to do before you can get other people to start playing your game. The first step is actually creating a release build of your game. Fortunately Unity makes this pretty easy. All you have to do is open up the Build Settings panel, select a platform, and create a build.
Once you have selected your platform, you may run into a few settings you need to change elsewhere in the project settings, but once you have that resolved all you do is start the build process and wait. Once the process is finished, you will have a folder on your hard drive which contains everything you need to run your game. Try running the executable, and your game should run just like it does in the Unity editor preview. From there you can do whatever you need to with the files, according to the process required to get your game published to your platform of choice.