Does the 100+ GB blockchain database contain every transaction? Does the 100+ GB blockchain database contain every transaction since the beginning, or only a digest of them?

I've read Nakamoto's paper and I see:


  the spent transactions before it can be discarded to save disk space [...] Merkle Tree  [...]


thus this question: is the 100+ GB blockchain already the result of a space-saving lossy process?
Blockchain contains every confirmed transaction since the beginning. There are some tricks to save disk space of course.