A bit too complicated, depends on year and model. Some Commodores were just Commodores.
Executive, Omega, Evoke. All base models at various times. Then Acclaim. Berlina. Calais.
The Acclaim was a safety pack version of the Executive.
The Berlina in the VT era was ‘nearly’ a Calais. It gradually went down spec heading towards the VF.
The Calais in the VN was top spec, but also got downgraded as the series progressed, that is why a Calais V was introduced.
The VN SS was originally a poverty pack V8 S. But it went upmarket as the series progressed, but then went back down market as the SSV and SSVR were introduced. Even then the SSV and SSVR were decontented to some degree towards the VF2.
The Vacationers were generally a option parts bin pack, with varying content depending on series.
If you are able to decipher the pecking order of the whole British royal family, you should be able to get familiar with the many variations of Commodores.