Cubase 10 working with ADSR Sample Manager


I have a question about ADSR Sample Manager working with Cubase 10.
ADSR as far as I know, shows all audio-samples (mp3 and waves) regardless where they are stored on your harddiscs in “Libraries” you can compile yourself.

Are (all) the audio-samples that are available in Cubase 10 also mp3 or wav?
Asking because I cannot find 1 or more folders where the Steinberg audio-samples are stored.

Would be a big help if I could use ALL my samples (including the Cubase ones and the EastWest ones) from just ONE program or VST within Cubase.