What is OnUs in banking?

Could you elaborate on what exactly OnUs means in the context of banking? Is it a specific service, a type of transaction, or a term related to customer responsibility? How does it differ from other similar banking terminologies? What kind of scenarios would typically involve the use of OnUs, and what are the potential benefits or drawbacks for customers? As a finance professional, I'm interested in understanding the intricacies of banking terminology and how they impact customers' experiences.