When compressing assets for .APK does whole projects assets get included? or just the scenes assets? prefabs?

Im trying to keep filesize good and small on android devices, so im curious, and couldnt find any information on this…

do all assets from my projects hierarchy get included in the APK for android? if not, do all the prefabs get included?

does unity know to take only the “used” prefabs/assets?

Im hoping someones informed about this, because if it is packing all my assets from the whole project, then there must be a bunch of wasted space…

It includes only reference assets, i.e. build settings define which scenes should be included and the references are traced from there. StreamingAssets folder is included always (if you have one) no matter if you reference assets from it or not.