For real-time synchronization of products and inventory between two Odoo instances:

Option 1: Cron Jobs (Easiest)

Syncs data periodically (e.g., every few minutes).

Pros: Easy to implement, flexible, less complex.

Cons: Not real-time, potential for conflicts if updates happen simultaneously.

Option 2: Database Replication (Complex)

Keeps data synchronized in real-time at the database level.

Pros: Real-time updates, ensures consistency.

Cons: Complex to set up and manage, requires advanced knowledge, potential for replication issues.

Recommendation: If real-time updates are crucial, go for Database Replication. If a small delay is acceptable, Cron Jobs can be a simpler solution.