Congratulations! You've gotten through the Permissions section!
To summarize, you've learned:
How smart functions interact with permissions (Lesson 1 or Docs: Rule Usage)
Who signs transactions (auth record!) (Lesson 2 or Docs: Signatures)
How auth records, roles, and rules are structured (Lesson 3 or Docs: Auth/Role/Rule Structure)
How rules work (Lesson 4 or Docs: _rule Predicate)