It's a little confusing. I sat down with pen and paper and made a diagram to help me visualize and understand it.

Notes, replies, reactions and zaps to other people's notes get published on your public inbox relays.

Replies, reactions, and zaps to your published notes and replies from other users get logged to your public inbox relays.

Private messages, both incoming and outgoing, get written to your DM Inbox relays.

Your drafts, and client app settings get written to and accessed from your Private Home relays.

Your local relay (Citrine) is used like a public outbox relay. It stores copies of all your published notes, replies, reactions, as well as information about zaps you've made.

Search is handled by your search (NIP-50) relays. These relays are queried whenever you conduct a search from your client app.

General relays are the foundation of your feed. They deliver everyone else's notes to your client to be viewed and accessed on your feeds.