SQL Express and SQL Standard Evaluation upon installation

SQL Express and SQL Standard Evaluation upon installation

hi all,

I am noticed that if i installed the zenon engineering studio, it package with the sql express version. I also noticed that if i installed only service engine and reporting, it also package with sql standard evaluation. I understand the purpose for sql expres where it stores the configuration. But what is the purpose of sql standard evaluation. can i choose to not installed it together?