Always there's going to be the elder and the younger. The elder mainframers were the ones who were mature adults when what they worked with slowly became computers. The younger were the ones who saw the computers emerge already as younger, some may have even pursued that work.
There are many similarities between them, but also differences.
Same with the other two, except that the younger PC generation may overlap more or less completely with the elder mobile generation... with some amount of abstentions either way.