Under the Specs they list PRESETS, SAMPLES, LOOPS, SIZE, etc. In general, I think "PRESETS" means Instruments. Once you purchase a pack, that SPECS information is no longer available. And then when you are browsing to load sounds, terminology is different. You see terms like "Instrument," "Instrument Loops," "Construction Kits," "Drum Elements," "Drum Loops," "Instrument Loops," etc.
Glancing at the expansions that I have, here is a quick rundown on what I'm seeing.
Brass Riffs: Loops, Instruments (the instruments are classified as "Hit" There are a lot of them -- like maybe 80? They can be played with the keyboard, but they are short stabs, falls, chords, etc. Note range is limited before it starts to sound munchinized. But definitely a lot of useable material).
Electric Piano: All Instruments, no loops. All Rhodes. No Wurly. About 10 presets. Full and "Lite" versions, Pan, Tremolo, Phaser, Dirt, variations.
Electro Pop: No Instruments. 4 folders: Construction Kits, Drum Elements, Drum Loops, Instrument Loops.
Funk: The only Instrument is Bass (acoustic and electric versions). Then it's Construction Kits, Drum Loops, Instrument Loops, Percussion Loops, Vocals.
Latin Percussion: All individual hits; no loops. Large variety.
Talk Vox: This is kind of a speciality pack. There are a lot of different types of vocal sounds, and they can be played with the keyboard. There also phrases and beatbox loops… I used some of these vocal sounds to create a kind of Organ instrument on my track "Synth Book."
Trip Hop: Drum Elements, Drum Loops, Sound Effects. No instruments per se, but again, the samples can be played from the keyboard to created "instruments" of a kind, with varying degrees of success.
Hope this helps. Remember that even though some packs may not have Instruments as such, you can use the samples as instruments and play them from the keyboard for unusual kinds of "instruments," as it were.