TLDR; there are 3 dimensions to privacy in crypto: confidentiality, anonymity, sender receiver unlinkability

Confidentiality
Hides transaction amounts but not sender or receiver.

K Anonymity
Masks identities within a group of k participants. Bigger sets mean stronger privacy.

Full Anonymity
Sender, receiver, and amount are all hidden. The strongest privacy—but hard to scale.

Sender Receiver Unlinkability
Prevents linking who paid whom, even if identities are known. Common in mixers.