Some people consider annotations to be a conversation with the author. But you're also having a conversation with yourself and your own thoughts. (Cross reference Niklas Luhmann's having a conversation with himself via his notes.)
Further, there are platforms like Hypothes.is or social platforms like Twitter where you can move the conversation out of the page and engage with others. However, for this Hypothes.is has more power because it keeps the conversation linked to the original text and the original context (which I'll explicitly translate here as "with the text") to underline the point.
cf:
cum (Latin)
: with
textus (Latin)
: tissue, web, texture, fabric, connection, language
contextus (Latin)
: context, connection, coherence, connexion, coherency, text