What is the difference between a customer-in strategy

A customer-in strategy focuses on providing an excellent experience to customers, while a function-out strategy focuses on enabling internal teams within their current confines.
A customer-in strategy focuses on bringing customers into your flywheel, while a function-out strategy focuses on more mathematical approaches to increasing revenue.
A customer-in strategy prioritized the needs of your customer-facing teams, while a function-out strategy emphasizes the importance of operations and other back office teams.
Customer-in and function-out are two different names for the same RevOps approach to creating a functional customer strategy.

What is the difference between a customer-in strategy and a function-out strategy?