How to display components using their selector in Angular 17

Right now I'm playing around with Angular 17 (Angular CLI: 17.0.0).

The directory is structured as follows:

/src    /app        /x            x.component.css            x.component.html            x.component.spec.ts            x.component.ts        app.component.css        app.component.html        app.component.spec.ts        app.component.ts        app.config.ts        app.routes.ts    /assets    favicon.ico    index.html    main.ts    styles.css

I want to include the content of my component x by adding <app-x></app-x> to app.component.html and importing x in app.component.ts. However the content of that component is not displayed in the app.

What am I doing wrong?