In IBM terminology, a Program temporary fix or Product temporary fix , sometimes depending on date, is a single bug fix, or group of fixes, distributed in a form ready to install for customers.
A PTF normally follows an APAR , and where an "APAR fix" was issued, the PTF "is a tested APAR" or set of APAR fixes. However, if an APAR is resolved as "Fixed If Next" or "Permanent Restriction" then there may be no PTF fixing it, only a subsequent release.