100% cocoa powder = 100% cocoa?

Hello, I would like to know if 100% cocoa powder is the same as, for example, Lindt 100% dark chocolate. I'm looking for a cheaper alternative to Lindt chocolate I have read that butter is contained in the cocoa powder and the actual cocoa content is only 25%. I wanted to buy these: https://www.korodrogerie.de/stark-entoeltes-bio-kakaopulver-1-kg?aw_dev=m&aw_target=&&utm_term=&utm_campaign=Google+PMax+Germany+All+Products&utm_source=adwords&utm_medium=ppc&hsa_acc=8966015506& hsa_cam=19860829152&hsa_grp=&hsa_ad=&hsa_src=x&hsa_tgt=&hsa_kw=&hsa_mt=&hsa_net=adwords&hsa_ver=3&…