A first party is a website that a user is intentionally and knowingly visiting, as displayed by the URL field of the browser, and the set of resources on the web operated by the same organization. In practice, we consider resources to belong to the same party if they are part of the same registrable domain: a public suffix plus one additional label. Example: site.example, www.site.example, and s.u.b.site.example are…
The same way with bosch.com and bosch.dev. One is a famous tools manufacturer, the other is a web developer.
It is impossible to guess the entity behind domain names by only the domain name.