What types of application file extensions exist for different platforms?

Application file extension types depend on the platform:

• Windows: .exe — executable files, .dll — dynamic libraries.
• macOS: .app — application packages, which are actually folders containing resources and binaries.
• Linux: usually executable files have no extension, but can be .bin or .run for installers.
• Mobile platforms:
  • Android: .apk — application package.
  • iOS: .ipa — application archive for installation.

For web applications, extensions can be .html, .js, .css, but these are not executable files, rather resources.

Thus, the file extension often indicates the type and platform of the application, but is not always necessary for launching (especially in Unix-like systems).