Most Mac applications come bundled as a .app package that you simply have to drag&drop into your Applications for them to show up in Launchpad and Alfred. Or, if an application is a bit more complex you usually get a .dmg file that then installs like any normal MSI package you are used to from windows.

Not Eclipse for OSX. The Eclipse project maintainers do provide a OSX binary, but it doesn't look like most OSX .app packages in that the extracted binaries are a folder that then contains a .app.

If you only copy over the .app file you'll not be able to start Eclipse as it's just a starter script and the real Eclipse is living in the extracted Zip. I used to just start eclipse wherever I unpacked it, but apparently the right way to install it is to simply copy the whole extracted eclipse folder over to your Applications. Even though the .app is not in /Applications directly OSX picks it up and it shows up in Launchpad.