RSC (React Server Component)とSSR (Server Side Rendering)は全くの別物です

It is important note that RSC and SSR are two very different things (that tend to be used together).

RSCとSSRはよく一緒に使われるものですが、別物です。

Since these steps are independent, they don't have to be done in the same process or even on the same machine.

RSCとSSRは独立しているのでそもそも同じプロセス・マシンで動かす必要もありません。