what is PA-RISC and IPF ?

[prasadb]

what is the meaning of term HP Precision Architecture Reduced Instruction Set Computing (PA-RISC) systems and Itanium Processor Family (IPF) system

[Venkatesh BL · Accepted solution]

Both are two different processor architectures...
http://en.wikipedia.org/wiki/PA-RISC
http://en.wikipedia.org/wiki/Itanium

[Mridul Shrivastava]

In addition to it, just from the point of end user.

In past you could only install HPUX on PA-RISC based Servers.

These days we could install other flavours like linux and windows on IPF platforms.

[Dennis Handly]

Most importantly, Integrity (see Venkatesh's link) it is EPIC (explicitly parallel instruction computing) instead of RISC.