Mainframe, MVS and zOS Discussion

I was reading about zIIP and zAAP and it is said that they offload the workload from general purpose processors. Would that mean that on an existing mainframe we'll "install" additional processor named "zIIP" adn "zAAP" ? Or they are part of software itself (though I doubt it) but if they are part of additional hardware howdo they save money or the TCO (Total coat of Ownership)? Please enlighten me.

because IBM ( until it changes it' s mind ) will not charge the <CPU> consumption of the zIIP and zAAP

googling with zIIP zAAP savings will provide lots of material to meditate on

zIIP and zAAP are processors -- as in hardware, not software. A z/OS system that has these processors (either or both types -- a customer can pick and choose) installed will have some of the work transferred to the specialty processor instead of using the main processor. Two advantages to specialty processors: charging for them is typically significantly less than the main (ICF) processor, and the specialty processors run at full speed no matter what the ICF processor runs at (i.e., no capping).

Thank you Robert.