The initiator dimension splits oracles into pull-based and push-based. What does each mean?

Pull = the receiver requests the data on demand (a request-response exchange); push = the sender proactively delivers it when something changes. Push/pull names who starts the transfer, not which direction the data moves.

Keep the two dimensions separate — "push" does not mean "onto the chain."

• Pull-based: the side that wants the data asks for it. It waits, sends a request, and gets a response back. Good when data is needed at a specific moment.
• Push-based: the side that has the data watches for relevant changes and sends them unprompted. Good for scattered or irregularly-updated data that the receiver couldn't easily poll for.

Because direction and initiator are orthogonal, "pull" can be initiated on-chain (pull-based inbound) or off-chain (pull-based outbound). Always read the two words together.