Hi,

lpp = licensed program product - a fileset, can be listed using lslpp or lslpp_r -R commands
bff = backup file format - native / default AIX package, can contain one to many filesets - AIX OS and Software installables + updates usually come in this format where U represents an update file, I a base package. Bffs can be committed or applied. Packages are automatically committed if they are base packages so no previous version exists, or applied when you install an update to an existing package - in which case the previous version is kept while you are using the updated version. Applied packages can be committed at some point in time (than all previous versions are removed) or rejected in which case you go back to the next latest applied if available or committed version of the same package.
APAR = authorized program analysis report - an officially by IBM recognized and diagnosed problem which usually leads to a released 'program temporary fix' - the so-called PTF which usually comes across as ifix which can be viewed / installed via instfix commands or as 'efix' package which is a compressed format and can be listed/installed using emgr commands.
Starting with AIX 5L, AIX supports as well the rpm package format. Microcodes for adapters come usually as rpm's.

I am sure I forgot something ... but still hope this helps.

Regards
zxmaus