Ithaca Freedom of Technology

Douglas Crawford at Proton wrote this great summary of the differences between anonymity and privacy. He notes that they are not synonyms and contrasts them:

Anonymity – Keeping your identity private, but not your actions. For example, using a pseudonym to post messages to a social media platform. Privacy – Keeping some things to yourself, which can include your actions. For example, messaging friends privately so they know who sent the message, but only they can read it.

So you can be anonymous but not private, and vice versa. You can also be both, or neither.