Backend plugins vs. frontend plugins

I am interested in the difference between a “frontend” theia plugin and a “backend” plugin. This question is about “plugins” only, it is clear for extensions.
I browsed through the code a bit and my current conclusion is that the only difference is the logging, but that the two types are processed exactly the same at the moment. VS Code extensions are processed as backend plugins by default.
Am I missing something?

[original thread by Jonas Helming]

it’s where callbacks are running
If you have frontend plug-ins, code will be running in webworker on browser side and not inside server side (like VS Code extension)

But if you’re using webviews, you can also have some code running in client side as well