Sure. But the clarifying words are useful in this context. It’s software; a web app that you can host yourself.

It specifically refers to client/server software where the server-side component is run within one's own server environment, and usually describes FOSS alternatives to SaaS webapps.

Normal desktop applications aren't self-hosted, as they aren't hosted in this sense to begin with.

I found the additional context to be helpful in quickly understanding how / where I could run it.