When I was much younger, I'd open the installation folder for desktop gaming applications and snoop around. I'd see thousands of files whose names I didn't understand then I'd see the usual setup, launch and uninstall files that I could recognize. The size of the actual launch game file was always so small for gaming apps that were terribly big. I sometimes made the mistake of thinking the launch file was the entire game, copying just that file and realizing the game doesn't run.

It took me years to find out that apps are broken into two file types in general; .exe and .dll. Files that have an .exe suffix are executable files, when you double click them they respond by launching something you can interact with, they're usually small files because their only job is to draw on the code written in .dll file types. .dll suffixed file types aren't executable, you don't interact with them. They're the engines of the apps you run. They contain the necessary code needed to create an app.

Depending on the size of an app, you can have thousands of .dll files in the folder, they're so important that an app may not run or may crash unexpectedly if one of such files are missing. DLL standards for (Dynamic Link Library). They respond only to the call of an .exe suffixed file type.