[Q] Can we use 4.4.x gapps on 4.3.x roms? topic

Hey guys!
I don't understand the why there are so many different gapps package. They seem all the same to me so I don't get it.
I began using custom roms since 4.4 kitkat because google ended support for your beloved nexus but now I want to go back to 4.3 a little and I am unsure on what gapps package should I use.